Functionally important residues at a subunit interface site in the RecA protein from Escherichia coli.

Molecular Mechanism Underlying ATP-Induced Conformational Changes in the Nucleoprotein Filament of Mycobacterium smegmatis RecA

“…Biochemical and biophysical experiments conducted over the past two decades have helped generate a broad outline of the molecular events that constitute the RecA catalytic cycle. ,,− The interaction of the carboxamide group of Gln194/196 with ATP leads to a conformational change in DNA binding loop L2, causing it to acquire an extended β-sheet conformation . The information is then transmitted along the peptide backbone of L2, to α-helix 8 downstream of L2, resulting in the insertion of a conserved phenylalanine (Phe217/219), into a hydrophobic pocket in the neighboring RecA molecule .…”

Intersubunit Proximity of Residues in the RecA Protein As Shown by Engineered Disulfide Cross-Links

“…While the mutational stringency at K216 and R222 can be rationalized in terms of the contacts observed in the crystal structure, there appear to be no structural constraints that explain the stringency at F217 (6). However, several hydrophobic residues are seen clustered within a pocket in the neighboring subunit and may serve to stabilize a crosssubunit interaction with F217.…”

“…In an effort to identify important determinants of the oligomeric structure of RecA, we previously introduced a number of mutations into one area of the protein (6) which is seen in the crystal structure (7) to contain a variety of intersubunit contacts. The sequence spanning residues 213-222 contains five amino acids (N213, K216, F217, Y218, and R222) whose side chains extend across the interface and contact positions in the neighboring subunit (6,7).…”

“…In an effort to identify important determinants of the oligomeric structure of RecA, we previously introduced a number of mutations into one area of the protein (6) which is seen in the crystal structure (7) to contain a variety of intersubunit contacts. The sequence spanning residues 213-222 contains five amino acids (N213, K216, F217, Y218, and R222) whose side chains extend across the interface and contact positions in the neighboring subunit (6,7). Of these five positions, we found that three are far more sensitive to substitution (F217 > K216 > R222) than the other two (N213 and Y218) with regard to inhibition of recombinational DNA repair and homologous recombination activities (6), and effects on coprotease function (M. C. Skiba and K. L. Knight, unpublished results).…”

“…The sequence spanning residues 213-222 contains five amino acids (N213, K216, F217, Y218, and R222) whose side chains extend across the interface and contact positions in the neighboring subunit (6,7). Of these five positions, we found that three are far more sensitive to substitution (F217 > K216 > R222) than the other two (N213 and Y218) with regard to inhibition of recombinational DNA repair and homologous recombination activities (6), and effects on coprotease function (M. C. Skiba and K. L. Knight, unpublished results). Of 15 substitutions at position 217, F217Y maintains wild-type-like recombination activities in vivo, F217C maintains approximately 20% of the recombination activities, and the 13 other substitutions, which include a variety of polar and nonpolar amino acids, result in complete inactivation of all RecA functions (ref 6, this study, and unpublished results of M. C. Skiba, K. M. Logan, S. Eldin, and K. L. Knight).…”