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1k0p

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Revision as of 13:08, 17 July 2019

NMR Structures of the Zinc Finger Domain of Human DNA Polymerase-alpha

Structural highlights

1k0p is a 1 chain structure. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance.
Related:	1k18
Activity:	DNA-directed DNA polymerase, with EC number 2.7.7.7
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[DPOLA_HUMAN] Plays an essential role in the initiation of DNA replication. During the S phase of the cell cycle, the DNA polymerase alpha complex (composed of a catalytic subunit POLA1/p180, a regulatory subunit POLA2/p70 and two primase subunits PRIM1/p49 and PRIM2/p58) is recruited to DNA at the replicative forks via direct interactions with MCM10 and WDHD1. The primase subunit of the polymerase alpha complex initiates DNA synthesis by oligomerising short RNA primers on both leading and lagging strands. These primers are initially extended by the polymerase alpha catalytic subunit and subsequently transferred to polymerase delta and polymerase epsilon for processive synthesis on the lagging and leading strand, respectively. The reason this transfer occurs is because the polymerase alpha has limited processivity and lacks intrinsic 3' exonuclease activity for proofreading error, and therefore is not well suited for replicating long complexes.^[1]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The carboxy terminus of the human DNA polymerase-alpha contains a zinc finger motif. Three-dimensional structures of this motif containing 38 amino acid residues, W L I C E E P T C R N R T R H L P L Q F S R T G P L C P A C M K A T L Q P E, were determined by nuclear magnetic resonance (NMR) spectroscopy. The structures reveal an alpha-helix-like domain at the amino terminus, extending 13 residues from L2 through H15 with an interruption at the sixth residue. The helix region is followed by three turns (H15-L18, T23-L26 and L26-A29), all of which involve proline. The first turn appears to be type III, judging by the dihedral angles. The second and third turns appear to be atypical. A second, shorter helix is formed at the carboxy terminus extending from C30 through L35. A fourth type III turn starting at L35 was also observed in the structure. Proline serves as the third residue of all the turns. Four cysteine residues, two located at the beginning of the helix at the N-terminus and two at the carboxy end, are coordinated to Zn(II), facilitating the formation of a loop. One of the cysteines at the carboxy terminus is part of the atypical turn, while the other is the part of the short helix. These structural features are consistent with the circular dichroism (CD) measurements which indicate the presence of 45% helix, 11% beta turns and 19% non-ordered secondary structures. The zinc finger motif described here is different from those observed for C(4), C(2)H(2), and C(2)HC modules reported in the literature. In particular, polymerase-alpha structures exhibit helix-turn-helix motif while most zinc finger proteins show anti-parallel sheet and helix. Several residues capable of binding DNA, T, R, N, and H are located in the helical region. These structural features imply that the zinc finger motif is most likely involved in binding DNA prior to replication, presumably through the helical region. These results are discussed in the context of other eukaryotic and prokaryotic DNA polymerases belonging to the polymerase B family.

Nuclear magnetic resonance structures of the zinc finger domain of human DNA polymerase-alpha.,Evanics F, Maurmann L, Yang WW, Bose RN Biochim Biophys Acta. 2003 Sep 23;1651(1-2):163-71. PMID:14499601^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Dantzer F, Nasheuer HP, Vonesch JL, de Murcia G, Menissier-de Murcia J. Functional association of poly(ADP-ribose) polymerase with DNA polymerase alpha-primase complex: a link between DNA strand break detection and DNA replication. Nucleic Acids Res. 1998 Apr 15;26(8):1891-8. PMID:9518481
↑ Evanics F, Maurmann L, Yang WW, Bose RN. Nuclear magnetic resonance structures of the zinc finger domain of human DNA polymerase-alpha. Biochim Biophys Acta. 2003 Sep 23;1651(1-2):163-71. PMID:14499601

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 See Also
6 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1k0p"

@@ Line 1: / Line 1: @@
 ==NMR Structures of the Zinc Finger Domain of Human DNA Polymerase-alpha==
-<StructureSection load='1k0p' size='340' side='right' caption='[[1k0p]], [[NMR_Ensembles_of_Models | 15 NMR models]]' scene=''>
+<StructureSection load='1k0p' size='340' side='right'caption='[[1k0p]], [[NMR_Ensembles_of_Models | 15 NMR models]]' scene=''>
 == Structural highlights ==
 <table><tr><td colspan='2'>[[1k0p]] is a 1 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1K0P OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1K0P FirstGlance]. <br>
@@ Line 14: / Line 14: @@
 Check<jmol>
   <jmolCheckbox>
-    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/k0/1k0p_consurf.spt"</scriptWhenChecked>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/k0/1k0p_consurf.spt"</scriptWhenChecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <text>to colour the structure by Evolutionary Conservation</text>
@@ Line 29: / Line 29: @@
 </div>
 <div class="pdbe-citations 1k0p" style="background-color:#fffaf0;"></div>
+==See Also==
+*[[DNA polymerase 3D structures|DNA polymerase 3D structures]]
 == References ==
 <references/>
@@ Line 34: / Line 37: @@
 </StructureSection>
 [[Category: DNA-directed DNA polymerase]]
+[[Category: Large Structures]]
 [[Category: Basu, S]]
 [[Category: Bose, R N]]

1k0p

From Proteopedia

Revision as of 13:08, 17 July 2019

NMR Structures of the Zinc Finger Domain of Human DNA Polymerase-alpha

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

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