Premium
The putative Walker A and Walker B motifs of R rp2 are required for the growth of B orrelia burgdorferi
Author(s) -
Ouyang Zhiming,
Zhou Jianli
Publication year - 2017
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13545
Subject(s) - biology , walker motifs , rpos , borrelia burgdorferi , enhancer , mutagenesis , genetics , gene , mutation , microbiology and biotechnology , biochemistry , atpase , atp hydrolysis , gene expression , promoter , enzyme , antibody
Summary Rrp2 encodes a putative bacterial enhancer binding protein (bEBP) in Borrelia burgdorferi . Point mutation (G239C) of Rrp2 abolishes the transcriptional activation of σ 54 ‐dependent rpoS . In contrast to canonical bEBPs that are dispensable for bacterial growth, Rrp2 is essential for borrelial growth in BSK medium. It has been believed that Rrp2's ATPase activity is not required for cell growth, but experimental evidence supporting this notion has been lacking. In particular, it has remained unclear whether the residue G239 is involved in Rrp2's presumptive ATPase activity. To address these information gaps, we examined the roles of Rrp2's potential strategic signatures including the G239 residue and the putative Walker A and Walker B motifs. Herein it was showed that Rrp2 has ATP binding and hydrolysis activities engendered by the Walker A and B motifs respectively. However, these activities were not significantly impaired by a G239C mutation. Further mutagenesis analyses indicated that Rrp2's Walker A and B motifs are required for borrelial growth; mutations of key residues in these two motifs were lethal to B. burgdorferi . The combined data suggest that the Walker A and Walker B motifs of Rrp2 are involved in the control of another unknown RpoS‐independent gene product(s) associated with borrelial replication.