MAW point mutation impairs H. Seropedicae RecA ATP hydrolysis and DNA repair without inducing large conformational changes in its structure

• Published in: PloS one Vol. 14; no. 4; p. e0214601
• Main Authors: Leite, Wellington C, Penteado, Renato F, Gomes, Fernando, Iulek, Jorge, Etto, Rafael M, Saab, Sérgio C, Steffens, Maria B R, Galvão, Carolina W
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 18.04.2019; Public Library of Science (PLoS)
• Subjects: Adenosine diphosphate; Adenosine triphosphatase; Adenosine Triphosphatases - metabolism; Adenosine Triphosphate - metabolism; Amino Acid Motifs; ATP; ATPases; Bacteria; Bacterial genetics; Binding Sites; Biochemistry; Bonds (Securities); Chemistry; Core loss; Deoxyribonucleic acid; DNA; DNA binding; DNA Repair; DNA, Single-Stranded - metabolism; E coli; Escherichia coli; Escherichia coli - metabolism; Escherichia coli - radiation effects; Gene mutation; Genetic aspects; Genetic research; Herbaspirillum - genetics; Hydrogen; Hydrogen bonds; Hydrolysis; Hydrophobicity; In vivo methods and tests; MMS (Multimedia messaging service); Molecular biology; Molecular dynamics; Molecular Dynamics Simulation; Mutation; Phenotypes; Physiological aspects; Point Mutation; Protein Binding; Protein Structure, Tertiary; Proteins; Proteobacteria; Rec A Recombinases - chemistry; Rec A Recombinases - genetics; Rec A Recombinases - metabolism; RecA protein; RecA proteins; Repair; Ultraviolet Rays; Brazil; California
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0214601

RecA is a multifunctional protein that plays a central role in DNA repair in bacteria. The structural Make ATP Work motif (MAW) is proposed to control the ATPase activity of RecA. In the present work, we report the biochemical activity and structural effects of the L53Q mutation at the MAW motif of the RecA protein from H. seropedicae (HsRecA L53Q). In vitro studies showed that HsRecA L53Q can bind ADP, ATP, and ssDNA, as does wild-type RecA. However, the ATPase and DNA-strand exchange activities were completely lost. In vivo studies showed that the expression of HsRecA L53Q in E. coli recA1 does not change its phenotype when cells were challenged with MMS and UV. Molecular dynamics simulations showed the L53Q point mutation did not cause large conformational changes in the HsRecA structure. However, there is a difference on dynamical cross-correlation movements of the residues involved in contacts within the ATP binding site and regions that hold the DNA binding sites. Additionally, a new hydrogen bond, formed between Q53 and T49, was hypothesized to allow an independent motion of the MAW motif from the hydrophobic core, what could explain the observed loss of activity of HsRecA L53Q.