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Yi Chuan Xue Bao. 2002 Dec;29(12):1111-7.

[Cloning and sequencing of the proBA gene from the selected mutant resistant to proline analogue from Bacillus subtilis].

[Article in Chinese]

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Department of Technology, College of Life Science, Wuhan University, Wuhan 430072, China.


NTG was used to make chemical mutation for Bacillus subtilis 93151. An enhanced osmotolerant mutant was obtained, which could grow in minimal medium containing 14% NaCl (w/v) and was not subject to proline-mediated feedback repression. The content of the intracellular free proline from the mutant increased rapidly with the rising of NaCl concentration. A 2.3 kb DNA fragment from the mutant was amplified using PCR method. Sequence analysis indicated that three bases changed within the proB gene, compared with the wild-type strain. One of the mutations was substitution of an A for a T at nt position 781, leading to a change of a Ser to a Thr at amino acid residue 261 of the deduced protein product, while other two were silent mutations. The recombinant vector pBE2-proB could functionally complement the proline auxotrophy E. coli 1.1252. Sequence analysis of proA showed that proA and proB overlapped by 4 nt, and there was a SD sequence at nt 14 upstream of the start codon of proA. The deduced amino acid of proA gene shared a high similarity with that of Bacillus subtilis 168 (77%).

[Indexed for MEDLINE]

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