Y. Abhayawardhane et Gc. Stewart, BACILLUS-SUBTILIS POSSESSES A 2ND DETERMINANT WITH EXTENSIVE SEQUENCESIMILARITY TO THE ESCHERICHIA-COLI-MREB MORPHOGENE, Journal of bacteriology, 177(3), 1995, pp. 765-773
A gene with substantial sequence similarity to the mreB morphogene of
Bacillus subtilis has been identified at 302 degrees on the chromosoma
l map by A, Decatur, B, Kunkel, and R. Losick (Harvard University; per
sonal communication). Our characterization has revealed that the prote
in product of this determinant (termed mbl for mreB-like) is 55 and 53
% identical in sequence to the MreB proteins of B. subtilis and Escher
ichia coli, respectively, The protein is 86% identical to a protein id
entified as MreB from Bacillus cereus, suggesting that the B, cereus p
rotein is actually Mbl. Insertional inactivation of mbl indicated that
this gene is not essential for cell viability or sporulation, Cells b
earing mutant mbl alleles display a decreased growth rate and an alter
ed cellular morphology. The cells appear bloated and are frequently tw
isted, Intergenic suppressor mutations which restore the growth rate t
o an approximately normal level arise within the mutant population. A
second site mutation, designated som-1, was mapped to the hisA-mbl reg
ion of the chromosome by transduction.