The anionic phospholipids in the plasma membrane play an important role in regulating the biochemical properties and biological functions of RecA proteins

Prasad, D and Muniyappa, K (2019) The anionic phospholipids in the plasma membrane play an important role in regulating the biochemical properties and biological functions of RecA proteins. In: Biochemistry .

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Abstract

Escherichia coli RecA (EcRecA) forms discrete foci that cluster at cell poles during normal growth, which are redistributed along the filamented cell axis upon induction of the SOS response. The plasma membrane is thought to act as a scaffold for EcRecA foci, thereby playing an important role in RecA-dependent homologous recombination. In addition, in vivo and in vitro studies demonstrate that EcRecA binds strongly to the anionic phospholipids. However, there have been almost no data on the association of mycobacterial RecA proteins with the plasma membrane and the effects of membrane components on their function. Here, we show that mycobacterial RecA proteins specifically interact with phosphatidylinositol and cardiolipin among other anionic phospholipids; however, they had no effect on the ability of RecA proteins to bind single-stranded DNA. Interestingly, phosphatidylinositol and cardiolipin impede the DNA-dependent ATPase activity of RecA proteins, although ATP binding is not affected. Furthermore, the ability of RecA proteins to promote DNA strand exchange is not affected by anionic phospholipids. Strikingly, anionic phospholipids suppress the RecA-stimulated autocatalytic cleavage of the LexA repressor. The Mycobacterium smegmatis RecA foci localize to the cell poles during normal growth, and these structures disassemble and reassemble into several foci along the cell after the induction of DNA damage. Taken together, these data support the notion that the interaction of RecA with cardiolipin and phosphatidylinositol, the major anionic phospholipids of the mycobacterial plasma membrane, may be physiologically relevant, as they provide a scaffold for RecA storage and may regulate recombinational DNA repair and the SOS response. © 2019 American Chemical Society.

Item Type:	Journal Article
Publication:	Biochemistry
Publisher:	American Chemical Society
Additional Information:	Copyright for this article belongs to American Chemical Society
Keywords:	Cell membranes; Cytology; Digital storage; DNA; Escherichia coli; Phospholipids; Physiological models; Poles; Proteins; Systems engineering, Anionic phospholipids; Biochemical properties; Biological functions; Dna strand exchanges; Homologous recombination; Membrane components; Mycobacterium smegmatis; Phosphatidylinositol, Scaffolds (biology)
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	08 Apr 2019 11:48
Last Modified:	08 Apr 2019 11:48
URI:	http://eprints.iisc.ac.in/id/eprint/62023

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