This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.


1vdj

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1vdj.gif|left|200px]]
+
{{Seed}}
 +
[[Image:1vdj.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1vdj| PDB=1vdj | SCENE= }}
{{STRUCTURE_1vdj| PDB=1vdj | SCENE= }}
-
'''Solution structure of actin-binding domain of troponin in Ca2+-bound state'''
+
===Solution structure of actin-binding domain of troponin in Ca2+-bound state===
-
==Overview==
+
<!--
-
Troponin and tropomyosin on actin filaments constitute a Ca2+-sensitive switch that regulates the contraction of vertebrate striated muscle through a series of conformational changes within the actin-based thin filament. Troponin consists of three subunits: an inhibitory subunit (TnI), a Ca2+-binding subunit (TnC), and a tropomyosin-binding subunit (TnT). Ca2+-binding to TnC is believed to weaken interactions between troponin and actin, and triggers a large conformational change of the troponin complex. However, the atomic details of the actin-binding sites of troponin have not been determined. Ternary troponin complexes have been reconstituted from recombinant chicken skeletal TnI, TnC, and TnT2 (the C-terminal region of TnT), among which only TnI was uniformly labelled with 15N and/or 13C. By applying NMR spectroscopy, the solution structures of a "mobile" actin-binding domain (approximately 6.1 kDa) in the troponin ternary complex (approximately 52 kDa) were determined. The mobile domain appears to tumble independently of the core domain of troponin. Ca2+-induced changes in the chemical shift and line shape suggested that its tumbling was more restricted at high Ca2+ concentrations. The atomic details of interactions between actin and the mobile domain of troponin were defined by docking the mobile domain into the cryo-electron microscopy (cryo-EM) density map of thin filament at low [Ca2+]. This allowed the determination of the 3D position of residue 133 of TnI, which has been an important landmark to incorporate the available information. This enabled unique docking of the entire globular head region of troponin into the thin filament cryo-EM map at a low Ca2+ concentration. The resultant atomic model suggests that troponin interacted electrostatically with actin and caused the shift of tropomyosin to achieve muscle relaxation. An important feature is that the coiled-coil region of troponin pushed tropomyosin at a low Ca2+ concentration. Moreover, the relationship between myosin and the mobile domain on actin filaments suggests that the latter works as a fail-safe latch.
+
The line below this paragraph, {{ABSTRACT_PUBMED_16061251}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 16061251 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_16061251}}
==About this Structure==
==About this Structure==
-
1VDJ is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VDJ OCA].
+
1VDJ is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VDJ OCA].
==Reference==
==Reference==
Line 31: Line 35:
[[Category: Tropomyosin]]
[[Category: Tropomyosin]]
[[Category: Troponin]]
[[Category: Troponin]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 12:24:40 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 05:04:41 2008''

Revision as of 02:04, 29 July 2008

Image:1vdj.png

Template:STRUCTURE 1vdj

Solution structure of actin-binding domain of troponin in Ca2+-bound state

Template:ABSTRACT PUBMED 16061251

About this Structure

1VDJ is a Single protein structure of sequence from Gallus gallus. Full experimental information is available from OCA.

Reference

Structural basis for Ca2+-regulated muscle relaxation at interaction sites of troponin with actin and tropomyosin., Murakami K, Yumoto F, Ohki SY, Yasunaga T, Tanokura M, Wakabayashi T, J Mol Biol. 2005 Sep 9;352(1):178-201. PMID:16061251

Page seeded by OCA on Tue Jul 29 05:04:41 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1vdj"
Personal tools