Figure 4. The OB fold domain is critical for drRecJ resection.
(A) The OB fold domain is shown in rainbow-colored diagrams. Residues involved in DNA binding are labeled and shown as sticks. (B) A comparison of DNA in the complex II (DNA with 5´-ssDNA overhang; orange) with complex III (ssDNA; white). Two conserved aromatic residues Tyr496 and Trp517 are shown as sticks (yellow). The black arrowhead indicates the position of stacking interaction between Tyr496 and the guanine base. (C) Quantification and plot of ssDNA and DNA with 5´-ssDNA overhang, which are processed by wild-type and mutant drRecJ proteins (alanine substitutions of key residues in the OB fold domain), using the same DNA substrate and reaction conditions as in Figure 1B. Data are represented as mean ± SEM.
Figure 4—figure supplement 1. Structural comparison of the OB fold from E. coli SSB (ecSSB), D. radiodurans SSB subunits (drSSB_NTD and drSSB_CTD), D. radiodurans RecO (drRecO) and human replication protein A subunits (RPA14, RPA32 and RPA70).
Their PDB accession codes are shown in parentheses and references can be found in the main text. The mixed five β-strands are labeled and shown in distinct colors. Four loops are labeled as L1-L4. Conserved aromatic residues in loop3 and loop4 are shown as sticks.