ATP-Mediated Changes in Cross-Subunit Interactions in the RecA Protein

• Published in: Biochemistry (Easton) 2001-09, Vol.40 (38), p.11382-11389
• Main Authors: Logan, Karen M, Forget, Anthony L, Verderese, John Paul, Knight, Kendall L
• Format: Article
• Language: English
• Subjects: Adenosine Triphosphate - metabolism; Amino Acid Substitution; Bacteriophage phi X 174 - genetics; Crystallography, X-Ray; Dimerization; Disulfides - analysis; DNA Damage; DNA, Single-Stranded - chemistry; DNA, Single-Stranded - radiation effects; DNA, Single-Stranded - ultrastructure; DNA, Viral - chemistry; DNA, Viral - radiation effects; DNA, Viral - ultrastructure; Escherichia coli - genetics; Escherichia coli - metabolism; Models, Molecular; Plasmids; Protein Conformation; Protein Structure, Secondary; Protein Subunits; Rec A Recombinases - chemistry; Rec A Recombinases - ultrastructure; recA protein; Recombinant Proteins - chemistry; Recombinant Proteins - radiation effects; Recombinant Proteins - ultrastructure; Ultraviolet Rays
• ISSN: 0006-2960; 1520-4995
• DOI: 10.1021/bi011081u

RecA protein undergoes ATP- and DNA-induced conformational changes that result in different helical parameters for free protein filaments versus RecA/ATP/DNA nucleoprotein filaments. Previous mutational studies of a particular region of the RecA oligomeric interface suggested that cross-subunit contacts made by residues K6 and R28 were more important for stabilization of free protein oligomers than nucleoprotein filaments [Eldin, S., et al. (2000) J. Mol. Biol. 299, 91−101]. Using mutant proteins with specifically engineered Cys substitutions, we show here that the efficiency of cross-subunit disulfide bond formation at certain positions in this region changes in the presence of ATP or ATP/DNA. Our results support the idea that specific cross-subunit interactions that occur within this region of the subunit interface are different in free RecA protein versus RecA/ATP/DNA nucleoprotein filaments.