1quq
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(New page: 200px<br /> <applet load="1quq" size="450" color="white" frame="true" align="right" spinBox="true" caption="1quq, resolution 2.5Å" /> '''COMPLEX OF REPLICATI...)
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Revision as of 16:50, 12 November 2007
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COMPLEX OF REPLICATION PROTEIN A SUBUNITS RPA14 AND RPA32
Overview
Replication protein A (RPA), the eukaryote single-stranded DNA-binding, protein (SSB), is a heterotrimer. The largest subunit, RPA70, which, harbours the major DNA-binding activity, has two DNA-binding domains that, each adopt an OB-fold. The complex of the two smaller subunits, RPA32 and, RPA14, has weak DNA-binding activity but the mechanism of DNA binding is, unknown. We have determined the crystal structure of the proteolytic core, of RPA32 and RPA14, which consists of the central two-thirds of RPA32 and, the entire RPA14 subunit. The structure revealed that RPA14 and the, central part of RPA32 are structural homologues. Each subunit contains a, central OB-fold domain, which also resembles the DNA-binding domains in, RPA70; an N-terminal extension that interacts with the central OB-fold, domain; and a C-terminal helix that mediate heterodimerization via a, helix-helix interaction. The OB-fold of RPA32, but not RPA14, possesses, additional similarity to the RPA70 DNA-binding domains, supporting a, DNA-binding role for RPA32. The discovery of a third and fourth OB-fold in, RPA suggests that the quaternary structure of SSBs, which in Bacteria and, Archaea are also tetramers of OB-folds, is conserved in evolution. The, structure also suggests a mechanism for RPA trimer formation.
About this Structure
1QUQ is a Protein complex structure of sequences from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The crystal structure of the complex of replication protein A subunits RPA32 and RPA14 reveals a mechanism for single-stranded DNA binding., Bochkarev A, Bochkareva E, Frappier L, Edwards AM, EMBO J. 1999 Aug 16;18(16):4498-504. PMID:10449415
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