Evidence that asgB encodes a DNA-binding protein essential for growth and development of Myxococcus xanthus
| Autor: | Brian J. Cantwell, Jack M. Davis, Jocelyne Mayor, L. Plamann |
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| Rok vydání: | 1994 |
| Předmět: |
Myxococcus xanthus
DNA Mutational Analysis Molecular Sequence Data Cell Communication Microbiology Open Reading Frames Bacterial Proteins Inosine Monophosphate Sigma factor Amino Acid Sequence RNA Messenger Molecular Biology Transcription factor Peptide sequence Gene Genetics Base Sequence Sequence Homology Amino Acid biology Nucleic acid sequence Promoter Gene Expression Regulation Bacterial Sequence Analysis DNA biology.organism_classification Null allele DNA-Binding Proteins Mutation Transcription Factors Research Article |
| Zdroj: | Journal of Bacteriology. 176:2013-2020 |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.176.7.2013-2020.1994 |
| Popis: | The asg mutants of Myxococcus xanthus are defective in production of extracellular A-signal, which serves as a cell density signal for fruiting-body development. The DNA sequence of asgB, one of the three asg genes, was determined. The deduced amino acid sequence of AsgB contains a DNA-binding helix-turn-helix motif near the C terminus. This putative helix-turn-helix is highly similar to the helix-turn-helix in region 4.2 of major sigma factors, which is the region that recognizes and interacts with -35 sequences of promoters. We propose that AsgB is a transcription factor that binds to DNA sequences similar to the -35 hexamer, TTGACA. Analyses of asgB RNA levels and expression of an asgB-lacZ translational fusion indicate that expression of asgB remains fairly constant during the transition from growth into early development. The mutation within the asgB480 allele was identified as an A-to-G transition that results in a threonine-to-alanine substitution in the predicted protein product. Attempts to replace the wild-type copy of asgB with a null allele failed, indicating that asgB may be essential for growth. |
| Databáze: | OpenAIRE |
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