3f1v

E. coli Beta Sliding Clamp, 148-153 Ala MutantE. coli Beta Sliding Clamp, 148-153 Ala Mutant

Structural highlights 3f1v is a 2 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: , Related: 1ok7 Gene: dnaN, b3701, JW3678 (Escherichia coli) Activity: DNA-directed DNA polymerase, with EC number 2.7.7.7 Resources: FirstGlance, OCA, RCSB, PDBsum 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 Sliding clamp proteins topologically encircle DNA and play vital roles in coordinating the actions of various DNA replication, repair, and damage tolerance proteins. At least three distinct surfaces of the Escherichia coli beta clamp interact physically with the DNA that it topologically encircles. We utilized mutant beta clamp proteins bearing G66E and G174A substitutions (beta159), affecting the single-stranded DNA-binding region, or poly-Ala substitutions in place of residues 148-HQDVR-152 (beta(148-152)), affecting the double-stranded DNA binding region, to determine the biological relevance of clamp-DNA interactions. As part of this work, we solved the X-ray crystal structure of beta(148-152), which verified that the poly-Ala substitutions failed to significantly alter the tertiary structure of the clamp. Based on functional assays, both beta159 and beta(148-152) were impaired for loading and retention on a linear primed DNA in vitro. In the case of beta(148-152), this defect was not due to altered interactions with the DnaX clamp loader, but rather was the result of impaired beta(148-152)-DNA interactions. Once loaded, beta(148-152) was proficient for DNA polymerase III (Pol III) replication in vitro. In contrast, beta(148-152) was severely impaired for Pol II and Pol IV replication and was similarly impaired for direct physical interactions with these Pols. Despite its ability to support Pol III replication in vitro, beta(148-152) was unable to support viability of E. coli. Nevertheless, physiological levels of beta(148-152) expressed from a plasmid efficiently complemented the temperature-sensitive growth phenotype of a strain expressing beta159 (dnaN159), provided that Pol II and Pol IV were inactivated. Although this strain was impaired for Pol V-dependent mutagenesis, inactivation of Pol II and Pol IV restored the Pol V mutator phenotype. Taken together, these results support a model in which a sophisticated combination of competitive clamp-DNA, clamp-partner, and partner-DNA interactions serve to manage the actions of the different E. coli Pols in vivo. Sliding clamp-DNA interactions are required for viability and contribute to DNA polymerase management in Escherichia coli.,Heltzel JM, Scouten Ponticelli SK, Sanders LH, Duzen JM, Cody V, Pace J, Snell EH, Sutton MD J Mol Biol. 2009 Mar 20;387(1):74-91. Epub 2009 Jan 30. PMID:19361435 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also DNA polymerase

spinqualitylabelsall models 3f1v, resolution 1.77Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image