Document Type

Article

Language

eng

Format of Original

12 p.

Publication Date

7-2012

Publisher

Elsevier

Source Publication

Journal of Molecular Biology

Source ISSN

0022-2836

Original Item ID

DOI: 10.1016/j.jmb.2012.04.022

Abstract

The tetrameric Escherichia coli single-stranded DNA (ssDNA) binding protein (Ec-SSB) functions in DNA metabolism by binding to ssDNA and interacting directly with numerous DNA repair and replication proteins. Ec-SSB tetramers can bind ssDNA in multiple DNA binding modes that differ in the extent of ssDNA wrapping. Here, we show that the structurally similar SSB protein from the malarial parasite Plasmodium falciparum (Pf-SSB) also binds tightly to ssDNA but does not display the same number of ssDNA binding modes as Ec-SSB, binding ssDNA exclusively in fully wrapped complexes with site sizes of 52–65 nt/tetramer. Pf-SSB does not transition to the more cooperative (SSB)35 DNA binding mode observed for Ec-SSB. Consistent with this, Pf-SSB tetramers also do not display the dramatic intra-tetramer negative cooperativity for binding of a second (dT)35 molecule that is evident in Ec-SSB. These findings highlight variations in the DNA binding properties of these two highly conserved homotetrameric SSB proteins, and these differences might be tailored to suit their specific functions in the cell.

Comments

Accepted version. Journal of Molecular Biology, Vol. 420, No. 4-5 (July 2012): 284-295. DOI.

Edwin Antony was affiliated with Washington University at time of publication.

NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Molecular Biology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Molecular Biology, VOL 420, ISSUE 4-5, July 2012, DOI.

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