F-actin - Revision history

Michal Harel at 09:44, 2 February 2016

2016-02-02T09:44:54Z

←Older revision		Revision as of 09:44, 2 February 2016
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-	<StructureSection load='2zwh' size='~~450~~' side='right' scene='' caption=''>	+	<StructureSection load='2zwh' size='350' side='right' scene='' caption='Rabbit α-actin complex with ADP and Ca+2 ion (PDB code [[2zwh]])'>
	[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [[actin]] proteins generally have structural roles in cells.		[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [[actin]] proteins generally have structural roles in cells.
	<br/>		<br/>

Alexander Berchansky at 11:24, 26 August 2013

2013-08-26T11:24:25Z

←Older revision		Revision as of 11:24, 26 August 2013
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	==== [http://en.wikipedia.org/wiki/Actin#Actomyosin_filaments Actin-Myosin] ====		==== [http://en.wikipedia.org/wiki/Actin#Actomyosin_filaments Actin-Myosin] ====
	The relatively flatter shape of F-actin as compared to G-actin allows myosin to preferentially bind F-actin over G-actin. This means that F-actin, not G-actin, is the functional form of actin. It composes a large part of the thin filaments in conjunction with mysoin to give muscle contractions<ref name="Holmes2"/><ref name="Holmes3>PMID:14508495</ref>. The structure of F-actin gives it large resistance to extensive forces, such as those experienced in muscle contraction<ref name="Mitchinson"/>.		The relatively flatter shape of F-actin as compared to G-actin allows myosin to preferentially bind F-actin over G-actin. This means that F-actin, not G-actin, is the functional form of actin. It composes a large part of the thin filaments in conjunction with mysoin to give muscle contractions<ref name="Holmes2"/><ref name="Holmes3>PMID:14508495</ref>. The structure of F-actin gives it large resistance to extensive forces, such as those experienced in muscle contraction<ref name="Mitchinson"/>.
		+	</StructureSection>
		+	__NOTOC__

	==3D structures of actin==		==3D structures of actin==

Alexander Berchansky at 11:22, 26 August 2013

2013-08-26T11:22:41Z

←Older revision		Revision as of 11:22, 26 August 2013
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-	<StructureSection load='2zwh' size='450' side='right' scene='~~Journal:JBSD:27/Cv/1~~' caption=''>	+	<StructureSection load='2zwh' size='450' side='right' scene='' caption=''>
	[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [[actin]] proteins generally have structural roles in cells.		[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [[actin]] proteins generally have structural roles in cells.
	<br/>		<br/>

Alexander Berchansky at 11:22, 26 August 2013

2013-08-26T11:22:19Z

←Older revision		Revision as of 11:22, 26 August 2013
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-	~~{{STRUCTURE_2zwh\| PDB~~=2zwh ~~\| SIZE~~=~~300\| SCENE~~= \|right~~\|CAPTION~~=~~F-actin from rabbit complex with ADP , [[2x8f]] }}~~	+	<StructureSection load='2zwh' size='450' side='right' scene='Journal:JBSD:27/Cv/1' caption=''>
	[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [[actin]] proteins generally have structural roles in cells.		[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [[actin]] proteins generally have structural roles in cells.
	<br/>		<br/>
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	== Assembly ==		== Assembly ==
-	<~~applet load~~='~~1j6z' size='250' color='black' frame='true' align='left' caption=~~'Globular Actin (G-actin)~~: PDB identifier~~ [http://www.rcsb.org/pdb/explore/explore.do?structureId=1J6Z 1J6Z].~~' scene='Sandbox_154/1j6z_black_true/2'/>~~	+	<scene name='Sandbox_154/1j6z_black_true/2'>Globular Actin (G-actin)</scene> ([http://www.rcsb.org/pdb/explore/explore.do?structureId=1J6Z 1J6Z]).
		+
	'''G-actin''' is the free monomeric form of actin which polymerizes to F-actin. The structures of globular and filamentous actin are distinct from one another in numerous ways, despite the fact that G-actin comprises F-actin. When the monomeric actin becomes polymerized into F-actin, the unit becomes flattened. Also, F-actin possesses an ATPase function which is minimal in G-actin. The domains and active site are the same in terms of constituent components and will be discussed later in terms of the F-actin monomer.		'''G-actin''' is the free monomeric form of actin which polymerizes to F-actin. The structures of globular and filamentous actin are distinct from one another in numerous ways, despite the fact that G-actin comprises F-actin. When the monomeric actin becomes polymerized into F-actin, the unit becomes flattened. Also, F-actin possesses an ATPase function which is minimal in G-actin. The domains and active site are the same in terms of constituent components and will be discussed later in terms of the F-actin monomer.

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	=== F-actin Monomer and Polymer ===		=== F-actin Monomer and Polymer ===
-	<~~applet load~~='~~2zwh' size='275' color='black' frame='true' align='left' caption=~~'Filamentous Actin Unit(F-actin), [[2zwh]]~~' scene='Sandbox_154/2zwh_regions/2'/>~~	+	<scene name='Sandbox_154/2zwh_regions/2'>Filamentous Actin Unit (F-actin)</scene> ([[2zwh]])

	==== Monomer ====		==== Monomer ====
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	==== Domains ====		==== Domains ====
-	<~~applet load~~='~~2zwh' size='275' color='black' frame='true' align='right' caption=~~'Filamentous Actin (F-actin), [[2zwh]]~~' scene='Sandbox_154/2zwh_black_domains/1'/>~~	+	<scene name='Sandbox_154/2zwh_black_domains/1'>Filamentous Actin (F-actin)</scene> ([[2zwh]])
		+
	The structure of a single unit of F-actin arises from one polypeptide chain with two domains. The nucleotide binding cleft, site of ATP hydrolysis, can be observed between the two domains. Movement of the domains allows for the open and closed F-actin conformations.		The structure of a single unit of F-actin arises from one polypeptide chain with two domains. The nucleotide binding cleft, site of ATP hydrolysis, can be observed between the two domains. Movement of the domains allows for the open and closed F-actin conformations.
	Domain movement is made possible by rotation about the <scene name='Sandbox_154/2zwh_helix_domains_2/1'> peptide bonds of residues 141-142 and 335-336</scene>, shown in purple. According to Oda et al., during the transition from G- to F- actin, Domain 2 is believed to tilt 20° and fit itself with Domain 1, thus giving a flatter conformation than the free G-actin. It is not certain whether this flattening occurs before or after ATP hydrolysis<ref name="oda" />. Holmes<ref name="Holmes2">PMID:2395461</ref> provides a simplified image of this domain movement and flattening[http://www.nature.com/nature/journal/v457/n7228/fig_tab/457389a_F2.html].		Domain movement is made possible by rotation about the <scene name='Sandbox_154/2zwh_helix_domains_2/1'> peptide bonds of residues 141-142 and 335-336</scene>, shown in purple. According to Oda et al., during the transition from G- to F- actin, Domain 2 is believed to tilt 20° and fit itself with Domain 1, thus giving a flatter conformation than the free G-actin. It is not certain whether this flattening occurs before or after ATP hydrolysis<ref name="oda" />. Holmes<ref name="Holmes2">PMID:2395461</ref> provides a simplified image of this domain movement and flattening[http://www.nature.com/nature/journal/v457/n7228/fig_tab/457389a_F2.html].

Michal Harel at 12:46, 19 March 2013

2013-03-19T12:46:22Z

←Older revision		Revision as of 12:46, 19 March 2013
Line 25:		Line 25:

	=== F-actin Monomer and Polymer ===		=== F-actin Monomer and Polymer ===
-	<applet load='2zwh' size='275' color='black' frame='true' align='left' caption='Filamentous Actin Unit(F-actin)' scene='Sandbox_154/2zwh_regions/2'/>	+	<applet load='2zwh' size='275' color='black' frame='true' align='left' caption='Filamentous Actin Unit(F-actin), [[2zwh]]' scene='Sandbox_154/2zwh_regions/2'/>

	==== Monomer ====		==== Monomer ====
Line 44:		Line 44:

	==== Domains ====		==== Domains ====
-	<applet load='2zwh' size='275' color='black' frame='true' align='right' caption='Filamentous Actin (F-actin)' scene='Sandbox_154/2zwh_black_domains/1'/>	+	<applet load='2zwh' size='275' color='black' frame='true' align='right' caption='Filamentous Actin (F-actin), [[2zwh]]' scene='Sandbox_154/2zwh_black_domains/1'/>
	The structure of a single unit of F-actin arises from one polypeptide chain with two domains. The nucleotide binding cleft, site of ATP hydrolysis, can be observed between the two domains. Movement of the domains allows for the open and closed F-actin conformations.		The structure of a single unit of F-actin arises from one polypeptide chain with two domains. The nucleotide binding cleft, site of ATP hydrolysis, can be observed between the two domains. Movement of the domains allows for the open and closed F-actin conformations.
	Domain movement is made possible by rotation about the <scene name='Sandbox_154/2zwh_helix_domains_2/1'> peptide bonds of residues 141-142 and 335-336</scene>, shown in purple. According to Oda et al., during the transition from G- to F- actin, Domain 2 is believed to tilt 20° and fit itself with Domain 1, thus giving a flatter conformation than the free G-actin. It is not certain whether this flattening occurs before or after ATP hydrolysis<ref name="oda" />. Holmes<ref name="Holmes2">PMID:2395461</ref> provides a simplified image of this domain movement and flattening[http://www.nature.com/nature/journal/v457/n7228/fig_tab/457389a_F2.html].		Domain movement is made possible by rotation about the <scene name='Sandbox_154/2zwh_helix_domains_2/1'> peptide bonds of residues 141-142 and 335-336</scene>, shown in purple. According to Oda et al., during the transition from G- to F- actin, Domain 2 is believed to tilt 20° and fit itself with Domain 1, thus giving a flatter conformation than the free G-actin. It is not certain whether this flattening occurs before or after ATP hydrolysis<ref name="oda" />. Holmes<ref name="Holmes2">PMID:2395461</ref> provides a simplified image of this domain movement and flattening[http://www.nature.com/nature/journal/v457/n7228/fig_tab/457389a_F2.html].

David Canner at 00:15, 28 July 2012

2012-07-28T00:15:44Z

←Older revision		Revision as of 00:15, 28 July 2012
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	{{STRUCTURE_2zwh\| PDB=2zwh \| SIZE=300\| SCENE= \|right\|CAPTION=F-actin from rabbit complex with ADP , [[2x8f]] }}		{{STRUCTURE_2zwh\| PDB=2zwh \| SIZE=300\| SCENE= \|right\|CAPTION=F-actin from rabbit complex with ADP , [[2x8f]] }}
-	[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [[actin]] proteins generally have structural roles in cells.	+	[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [[actin]] proteins generally have structural roles in cells.
		+	<br/>
	{{TOC limit\|2}}		{{TOC limit\|2}}
	== Introduction ==		== Introduction ==

David Canner at 00:15, 28 July 2012

2012-07-28T00:15:20Z

←Older revision		Revision as of 00:15, 28 July 2012
Line 1:		Line 1:
	{{STRUCTURE_2zwh\| PDB=2zwh \| SIZE=300\| SCENE= \|right\|CAPTION=F-actin from rabbit complex with ADP , [[2x8f]] }}		{{STRUCTURE_2zwh\| PDB=2zwh \| SIZE=300\| SCENE= \|right\|CAPTION=F-actin from rabbit complex with ADP , [[2x8f]] }}
	[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [[actin]] proteins generally have structural roles in cells.		[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [[actin]] proteins generally have structural roles in cells.
-		+	{{TOC limit\|2}}
	== Introduction ==		== Introduction ==
	Actin is found in nearly all eukaryotic cells and is known primarily for its function as a structural and translocation protein. It also has an ATPase function, as it hydrolyzes ATP to ADP and P<sub>i</sub> and undergoes conformational changes with each hydrolysis. Actin belongs to the actin superfamily, which includes other proteins such as Hsp70(DnaK), Hsc70, and hexokinase, because of its nucleotide-dependent conformational change<ref name="Graceffa">PMID:12813032</ref>. Because of the similarity observed in ''Escherichia Coli'''s, Hsc70 and ATPase domain of actin, it is believed that the two proteins have a common ancestry<ref name="Holmes1">PMID:19158779</ref>. Prokaryotes are not known to have actin, but do however have an actin homologue, MreB, which also leads to the idea of possible common ancestory<ref name="Holmes2">PMID:2395461</ref>.		Actin is found in nearly all eukaryotic cells and is known primarily for its function as a structural and translocation protein. It also has an ATPase function, as it hydrolyzes ATP to ADP and P<sub>i</sub> and undergoes conformational changes with each hydrolysis. Actin belongs to the actin superfamily, which includes other proteins such as Hsp70(DnaK), Hsc70, and hexokinase, because of its nucleotide-dependent conformational change<ref name="Graceffa">PMID:12813032</ref>. Because of the similarity observed in ''Escherichia Coli'''s, Hsc70 and ATPase domain of actin, it is believed that the two proteins have a common ancestry<ref name="Holmes1">PMID:19158779</ref>. Prokaryotes are not known to have actin, but do however have an actin homologue, MreB, which also leads to the idea of possible common ancestory<ref name="Holmes2">PMID:2395461</ref>.

	Actin occurs in two forms: globular actin (G-actin), the free monomeric units of actin, and filamentous actin (F-actin) which is the polymer form. These two forms exist in a dynamic equilibrium with one another as ATP-associated polymerization and depolymerization occur continuously within the cell. The monomer units in the F-actin possess a form that is distinct from the free monomeric form and it is a result of that change that the more specific ATPase activity may be observed.		Actin occurs in two forms: globular actin (G-actin), the free monomeric units of actin, and filamentous actin (F-actin) which is the polymer form. These two forms exist in a dynamic equilibrium with one another as ATP-associated polymerization and depolymerization occur continuously within the cell. The monomer units in the F-actin possess a form that is distinct from the free monomeric form and it is a result of that change that the more specific ATPase activity may be observed.
-	~~__TOC__~~	+
	== Assembly ==		== Assembly ==
	<applet load='1j6z' size='250' color='black' frame='true' align='left' caption='Globular Actin (G-actin): PDB identifier [http://www.rcsb.org/pdb/explore/explore.do?structureId=1J6Z 1J6Z].' scene='Sandbox_154/1j6z_black_true/2'/>		<applet load='1j6z' size='250' color='black' frame='true' align='left' caption='Globular Actin (G-actin): PDB identifier [http://www.rcsb.org/pdb/explore/explore.do?structureId=1J6Z 1J6Z].' scene='Sandbox_154/1j6z_black_true/2'/>

David Canner at 00:11, 28 July 2012

2012-07-28T00:11:37Z

←Older revision		Revision as of 00:11, 28 July 2012
Line 6:		Line 6:

	Actin occurs in two forms: globular actin (G-actin), the free monomeric units of actin, and filamentous actin (F-actin) which is the polymer form. These two forms exist in a dynamic equilibrium with one another as ATP-associated polymerization and depolymerization occur continuously within the cell. The monomer units in the F-actin possess a form that is distinct from the free monomeric form and it is a result of that change that the more specific ATPase activity may be observed.		Actin occurs in two forms: globular actin (G-actin), the free monomeric units of actin, and filamentous actin (F-actin) which is the polymer form. These two forms exist in a dynamic equilibrium with one another as ATP-associated polymerization and depolymerization occur continuously within the cell. The monomer units in the F-actin possess a form that is distinct from the free monomeric form and it is a result of that change that the more specific ATPase activity may be observed.
-		+	__TOC__
	== Assembly ==		== Assembly ==
	<applet load='1j6z' size='250' color='black' frame='true' align='left' caption='Globular Actin (G-actin): PDB identifier [http://www.rcsb.org/pdb/explore/explore.do?structureId=1J6Z 1J6Z].' scene='Sandbox_154/1j6z_black_true/2'/>		<applet load='1j6z' size='250' color='black' frame='true' align='left' caption='Globular Actin (G-actin): PDB identifier [http://www.rcsb.org/pdb/explore/explore.do?structureId=1J6Z 1J6Z].' scene='Sandbox_154/1j6z_black_true/2'/>

David Canner at 00:10, 28 July 2012

2012-07-28T00:10:04Z

←Older revision		Revision as of 00:10, 28 July 2012
Line 1:		Line 1:
	{{STRUCTURE_2zwh\| PDB=2zwh \| SIZE=300\| SCENE= \|right\|CAPTION=F-actin from rabbit complex with ADP , [[2x8f]] }}		{{STRUCTURE_2zwh\| PDB=2zwh \| SIZE=300\| SCENE= \|right\|CAPTION=F-actin from rabbit complex with ADP , [[2x8f]] }}
-	[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [~~http://en.wikipedia.org/wiki/actin~~ actin] proteins generally have structural roles in cells.	+	[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [[actin]] proteins generally have structural roles in cells.

	== Introduction ==		== Introduction ==

David Canner at 00:09, 28 July 2012

2012-07-28T00:09:23Z

←Older revision		Revision as of 00:09, 28 July 2012
Line 1:		Line 1:
-	[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]
	{{STRUCTURE_2zwh\| PDB=2zwh \| SIZE=300\| SCENE= \|right\|CAPTION=F-actin from rabbit complex with ADP , [[2x8f]] }}		{{STRUCTURE_2zwh\| PDB=2zwh \| SIZE=300\| SCENE= \|right\|CAPTION=F-actin from rabbit complex with ADP , [[2x8f]] }}
-		+	[[Image:2zwh.png\|left\|200px\|thumb\|Crystal Structure of F-actin, [[2zwh]]]]'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [http://en.wikipedia.org/wiki/actin actin] proteins generally have structural roles in cells.
-		+
-	'''Filamentous actin''' ('''F-actin''') units are also referred to as [http://en.wikipedia.org/wiki/microfilament microfilaments] <ref> Microfilaments - Wikipedia, the free encyclopedia. http://en.wikipedia.org/wiki/Microfilament. Date accessed: March 16th, 2010. </ref> and are highly conserved, proteinous components found near ubiquitously in eukaryotic cytoskeletons. F-actin and other [http://en.wikipedia.org/wiki/actin actin] proteins generally have structural roles in cells.	+

	== Introduction ==		== Introduction ==