User:Udayan Shevade/Sandbox1
From Proteopedia
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==== The Origin Binding Domain ==== | ==== The Origin Binding Domain ==== | ||
| - | The central obd monomer consists of a five-stranded anti-parallel beta sheet flanked by two pairs of alpha helices. These molecules arrange tightly into a hexameric left-handed spiral, with 6 obd's per turn. Side-side interaction is crucial in hexamerization, for which residues Phe 183 and Ser 185 are crucial. The conformation creates a central channel 60 Angstrom wide, large enough for double stranded DNA, and is highly positively charged. The pitch of the crystallized spiral complements that of the DNA, | + | The central obd monomer consists of a five-stranded anti-parallel beta sheet flanked by two pairs of alpha helices. These molecules arrange tightly into a hexameric left-handed spiral, with 6 obd's per turn. Side-side interaction is crucial in hexamerization, for which residues Phe 183 and Ser 185 are crucial. The conformation creates a central channel 60 Angstrom wide, large enough for double stranded DNA, and is highly positively charged. The pitch of the crystallized spiral complements that of the DNA, bringing the sequence-specific regions of the obd's near GAGGC pentanucleotides of the origin. Along the inner surface of the channel, residues implicated in DNA binding are Asn 153, Arg 154, Thr 155 from the A motif; His 203, Arg 204 from the B2 motif; as well as His 201 and Arg 202. <ref name="A"/>.</StructureSection> |
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| + | ==== Helicase ==== | ||
Revision as of 00:18, 11 November 2011
Contents |
SV40 Large T Antigen
Introduction
The SV40 large T antigen is a multifunctional regulatory protein encoded by Simian Virus 40, belonging to the AAA+ family of helicases [1]. It is responsible for initiation of DNA replication, regulation of transcription and alteration of the host cell cycle to promote infectivity. Large T antigen is an early gene product of SV40 and is translated via differential mRNA splicing.
Structure
T-antigen consists of an N-terminal J domain, a central origin-binding domain, and a C-terminal helicase domain [1].
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