Interaction of RecA protein with acidic phospholipids inhibits DNA-binding activity of RecA

Abstract

The RecA protein of Escherichia coli plays a central role in both homologous genetic recombination and the induction of the SOS repair system. It displays a number of activities in vitro which include single-stranded DNA (ssDNA) and double-stranded DNA binding, DNA-dependent ATPase activity, DNA-and ATP-dependent catalysis of repressor cleavage, and pairing of homologous DNA molecules and subsequent strand exchange (for reviews, see references 7 and 12). The major in vivo processes in which the RecA protein participates depend on these activities. For example, the regulatory role of RecA in SOS is mediated by its capacity to catalyze cleavage of the LexA repressor: the induction of the SOS response is triggered by an inducing signal, generated in response to DNA damage, that activates RecA protein to mediate the proteolytic cleavage of LexA protein, the repressor of several SOS genes. Hydrolysis of LexA inactivates its repressor activity, allowing transcription of the target genes (including the recA gene itself) and the expression of the different SOS functions. High levels of RecA generated in this process presumably contribute to cell survival by participating in DNA repair and recombination (for reviews, see references 27 and 43).Several reports indicate that membrane fractions of SOSinduced cells contain elevated quantities of RecA protein (13,(16)(17)(18). In fact, the discovery of the role of the RecA protein in regulating the SOS response goes back to the early observations of Inouye and Pardee (18), who demonstrated that certain membrane proteins of E. coli were altered when DNA synthesis was inhibited. In particular, a 40,000-dalton protein termed protein X, which later turned out to be the RecA protein, was found to be markedly induced by a number of agents that adversely affected DNA metabolism. The amplification of the RecA protein during the SOS response is understandable in view of its contribution to cell survival. However, neither the significance nor the nature of * Corresponding author. t Present address:

Super‐resolution imaging reveals changes in Escherichia coli SSB localization in response to DNA damage

“…Corrected data in each titration were fit to one-site specific binding equation: Y = (B max × X)/(K d + X . ) as described previously (Rajendram et al, 2015) T A B L E 1 SSB binds to liposomes These data show that, like the DNA-binding proteins RecA and DnaA, SSB binds to the anionic phospholipid components of the inner membrane (Krishna & van de Sande, 1990;Makise, Mima, Katsu, Tsuchiya, & Mizushima, 2002;Rajendram et al, 2015). However, and unlike RecA, SSB also demonstrates an affinity for the zwitterionic phospholipid PE, as indicated by a K d value of 0.56 ± 0.20 µM observed in the presence of 80:20 PC:PE liposomes (Table 1).…”

“…These data show that, like the DNA‐binding proteins RecA and DnaA, SSB binds to the anionic phospholipid components of the inner membrane (Krishna & van de Sande, ; Makise, Mima, Katsu, Tsuchiya, & Mizushima, ; Rajendram et al, ). However, and unlike RecA, SSB also demonstrates an affinity for the zwitterionic phospholipid PE, as indicated by a K d value of 0.56 ± 0.20 µM observed in the presence of 80:20 PC:PE liposomes (Table ).…”

Super-resolution imaging reveals changes inEscherichia coliSSB localization in response to DNA damage

“…These data show that SSB, like RecA and DnaA, binds to the anionic phospholipid components of the inner membrane (27, 31, 32). However, and unlike RecA, SSB also demonstrates an affinity for the zwitterionic phospholipid PE, as indicated by a K d value of 0.56 ± 0.20 μM observed in the presence of 80:20 PC:PE liposomes (Table I).…”

Pathogenesis and Diseases of the Central Nervous System Caused by Murine Coronaviruses

“…Since N binds the viral M pro tein (Sturman et al, 1980) and the M protein is found in association with smooth endoplasmic reticulum (ER) membranes (Rottier and Rose, 1987), the membrane attachment may be mediated by the M. Nevertheless, N protein is able to associate with cellular membranes in the absence of M (Anderson and Wong, 1993), raising the possibility that the components involved are certain membrane phospholipids (Anderson and Wong, 1993). Interestingly, the ability of N to bind both membrane phospholipids and nucleic acid is perhaps analogous to that shown by certain bacterial DNA-binding pro teins such as DnaA (Sekimizu and Kornberg, 1988) and RecA (Krishna and van de Sande, 1990). The possibility, therefore, arises that an association of N with viral RNA is influenced by competitive binding to membrane phospholipids.…”