2itj: Difference between revisions

Revision as of 18:55, 21 February 2008

Origin binding domain of the SV40 large T antigen (residues 131-259). P212121 crystal form

OverviewOverview

The large T antigen (T-ag) protein binds to and activates DNA replication from the origin of DNA replication (ori) in simian virus 40 (SV40). Here, we determined the crystal structures of the T-ag origin-binding domain (OBD) in apo form, and bound to either a 17 bp palindrome (sites 1 and 3) or a 23 bp ori DNA palindrome comprising all four GAGGC binding sites for OBD. The T-ag OBDs were shown to interact with the DNA through a loop comprising Ser147-Thr155 (A1 loop), a combination of a DNA-binding helix and loop (His203-Asn210), and Asn227. The A1 loop traveled back-and-forth along the major groove and accounted for most of the sequence-determining contacts with the DNA. Unexpectedly, in both T-ag-DNA structures, the T-ag OBDs bound DNA independently and did not make direct protein-protein contacts. The T-ag OBD was also captured bound to a non-consensus site ATGGC even in the presence of its canonical site GAGGC. Our observations taken together with the known biochemical and structural features of the T-ag-origin interaction suggest a model for origin unwinding.

About this StructureAbout this Structure

2ITJ is a Single protein structure of sequence from Simian virus 40. Full crystallographic information is available from OCA.

ReferenceReference

Structure of the origin-binding domain of simian virus 40 large T antigen bound to DNA., Bochkareva E, Martynowski D, Seitova A, Bochkarev A, EMBO J. 2006 Dec 13;25(24):5961-9. Epub 2006 Nov 30. PMID:17139255

Page seeded by OCA on Thu Feb 21 17:55:48 2008

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OCA

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 ==Overview==
-The large T antigen (T-ag) protein binds to and activates DNA replication, from the origin of DNA replication (ori) in simian virus 40 (SV40). Here, we determined the crystal structures of the T-ag origin-binding domain, (OBD) in apo form, and bound to either a 17 bp palindrome (sites 1 and 3), or a 23 bp ori DNA palindrome comprising all four GAGGC binding sites for, OBD. The T-ag OBDs were shown to interact with the DNA through a loop, comprising Ser147-Thr155 (A1 loop), a combination of a DNA-binding helix, and loop (His203-Asn210), and Asn227. The A1 loop traveled back-and-forth, along the major groove and accounted for most of the sequence-determining, contacts with the DNA. Unexpectedly, in both T-ag-DNA structures, the T-ag, OBDs bound DNA independently and did not make direct protein-protein, contacts. The T-ag OBD was also captured bound to a non-consensus site, ATGGC even in the presence of its canonical site GAGGC. Our observations, taken together with the known biochemical and structural features of the, T-ag-origin interaction suggest a model for origin unwinding.
+The large T antigen (T-ag) protein binds to and activates DNA replication from the origin of DNA replication (ori) in simian virus 40 (SV40). Here, we determined the crystal structures of the T-ag origin-binding domain (OBD) in apo form, and bound to either a 17 bp palindrome (sites 1 and 3) or a 23 bp ori DNA palindrome comprising all four GAGGC binding sites for OBD. The T-ag OBDs were shown to interact with the DNA through a loop comprising Ser147-Thr155 (A1 loop), a combination of a DNA-binding helix and loop (His203-Asn210), and Asn227. The A1 loop traveled back-and-forth along the major groove and accounted for most of the sequence-determining contacts with the DNA. Unexpectedly, in both T-ag-DNA structures, the T-ag OBDs bound DNA independently and did not make direct protein-protein contacts. The T-ag OBD was also captured bound to a non-consensus site ATGGC even in the presence of its canonical site GAGGC. Our observations taken together with the known biochemical and structural features of the T-ag-origin interaction suggest a model for origin unwinding.
 ==About this Structure==
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 [[Category: dna binding protein]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jan 29 20:46:29 2008''
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