2a1k: Difference between revisions

Revision as of 17:22, 21 February 2008

RB69 single-stranded DNA binding protein core domain

OverviewOverview

In vivo, replicative DNA polymerases are made more processive by their interactions with accessory proteins at the replication fork. Single-stranded DNA binding protein (SSB) is an essential protein that binds tightly and cooperatively to single-stranded DNA during replication to remove adventitious secondary structures and protect the exposed DNA from endogenous nucleases. Using information from high resolution structures and biochemical data, we have engineered a functional chimeric enzyme of the bacteriophage RB69 DNA polymerase and SSB with substantially increased processivity. Fusion of RB69 DNA polymerase with its cognate SSB via a short six amino acid linker increases affinity for primer-template DNA by sixfold and subsequently increases processivity by sevenfold while maintaining fidelity. The crystal structure of this fusion protein was solved by a combination of multiwavelength anomalous diffraction and molecular replacement to 3.2 A resolution and shows that RB69 SSB is positioned proximal to the N-terminal domain of RB69 DNA polymerase near the template strand channel. The structural and biochemical data suggest that SSB interactions with DNA polymerase are transient and flexible, consistent with models of a dynamic replisome during elongation.

About this StructureAbout this Structure

2A1K is a Single protein structure of sequence from Enterobacteria phage rb18 with as ligand. Full crystallographic information is available from OCA.

ReferenceReference

Structure and enzymatic properties of a chimeric bacteriophage RB69 DNA polymerase and single-stranded DNA binding protein with increased processivity., Sun S, Geng L, Shamoo Y, Proteins. 2006 Oct 1;65(1):231-8. PMID:16881051

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OCA

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 ==Overview==
-In vivo, replicative DNA polymerases are made more processive by their, interactions with accessory proteins at the replication fork., Single-stranded DNA binding protein (SSB) is an essential protein that, binds tightly and cooperatively to single-stranded DNA during replication, to remove adventitious secondary structures and protect the exposed DNA, from endogenous nucleases. Using information from high resolution, structures and biochemical data, we have engineered a functional chimeric, enzyme of the bacteriophage RB69 DNA polymerase and SSB with substantially, increased processivity. Fusion of RB69 DNA polymerase with its cognate SSB, via a short six amino acid linker increases affinity for primer-template, DNA by sixfold and subsequently increases processivity by sevenfold while, maintaining fidelity. The crystal structure of this fusion protein was, solved by a combination of multiwavelength anomalous diffraction and, molecular replacement to 3.2 A resolution and shows that RB69 SSB is, positioned proximal to the N-terminal domain of RB69 DNA polymerase near, the template strand channel. The structural and biochemical data suggest, that SSB interactions with DNA polymerase are transient and flexible, consistent with models of a dynamic replisome during elongation.
+In vivo, replicative DNA polymerases are made more processive by their interactions with accessory proteins at the replication fork. Single-stranded DNA binding protein (SSB) is an essential protein that binds tightly and cooperatively to single-stranded DNA during replication to remove adventitious secondary structures and protect the exposed DNA from endogenous nucleases. Using information from high resolution structures and biochemical data, we have engineered a functional chimeric enzyme of the bacteriophage RB69 DNA polymerase and SSB with substantially increased processivity. Fusion of RB69 DNA polymerase with its cognate SSB via a short six amino acid linker increases affinity for primer-template DNA by sixfold and subsequently increases processivity by sevenfold while maintaining fidelity. The crystal structure of this fusion protein was solved by a combination of multiwavelength anomalous diffraction and molecular replacement to 3.2 A resolution and shows that RB69 SSB is positioned proximal to the N-terminal domain of RB69 DNA polymerase near the template strand channel. The structural and biochemical data suggest that SSB interactions with DNA polymerase are transient and flexible, consistent with models of a dynamic replisome during elongation.
 ==About this Structure==
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 [[Category: zn2+ binding subdomain]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jan 29 17:52:27 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:22:44 2008''