RT Journal Article SR Electronic(1) A1 Tiwari, Ravi P. A1 Reeve, Wayne G. A1 Dilworthan, Michael J. A1 Glenn, Andrew R.YR 1996 T1 An Essential Role for actA in Acid Tolerance of Rhizobium Melilotix JF Microbiology, VO 142 IS 3 SP 601 OP 610 DO https://doi.org/10.1099/13500872-142-3-601 PB Microbiology Society, SN 1465-2080, AB The actA gene, which is disrupted by Tn5 in the acid-sensitive mutant of Rhizobium meliloti TG2-6, was cloned and sequenced. It encodes a protein of 541 amino acids with a calculated molecular mass of 57963 Da and an estimated pI of 9.0. The ActA protein sequence has 30% identity, and much higher similarity (69%), with the CutE protein of Escherichia coli. Like the cutE mutant of E. coli TG2-6 is sensitive to copper. The reconstructed wild-type actA gene complemented the low pH- and copper-sensitive phenotype of TG2-6. Studies with an actA-lacZ gene fusion showed that actA is constitutively expressed at pH 5.8 and 7.0. The actA gene appears to be chromosomal and is present in all seven strains of R. meliloti tested., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/13500872-142-3-601