| Autor: |
CHOI, Il-Dong, HA, Gyong-Sik, KIM, Kyung-Nam, CHOI, Yong-Jin |
| Zdroj: |
Bioscience, Biotechnology, and Biochemistry; January 2004, Vol. 68 Issue: 7 p1414-1423, 10p |
| Abstrakt: |
The gene encoding the catabolite control protein A (CcpA) of Bacillus stearothermophilusNo. 236, a strong xylanolytic bacterium, was cloned, sequenced, and expressed in Escherichia coli. The nucleotide sequence of the ccpAgene corresponded to an open reading frame of 1,005 bp that encodes a polypeptide of 334 amino acid residues with a calculated molecular mass of 36,902 kDa. The CcpA protein belonging to the LacI/GalR family of transcriptional regulators was produced by a recombinant E. colistrain expressing the B. stearothermophilusNo. 236 ccpAgene and purified to apparent homogeneity. The transcription start site was mapped at a position 63 nucleotides upstream of the translation initiation codon, and a presumed promoter sequence was also identified. The deduced amino acid sequence of the ccpAgene product contained the helix-turn-helix motif found in many DNA-binding proteins, and showed the highest identity (62%) with CcpA from B. subtilis. The B. stearothermophilusNo. 236 ccpAgene was demonstrated to be able to complement a B. subtilis ccpAmutant that exhibited two distinct mutant phenotypes: a growth defect and a release of carbon catabolite repression (CCR). These results indicate that the ccpAgene product of B. stearothermophilusNo. 236 is functionally active also in B. subtilis. Electrophoretic mobility shift assay with the purified CcpA revealed that the CcpA of B. stearothermophilusNo. 236 bound specifically to the xynA creB (catabolite responsive element B) sequence. Taken together, these results strongly suggest that the CcpA protein participates in CCR of B. stearothermophilusNo. 236 xynAgene. |
| Databáze: |
Supplemental Index |
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