THE BLDD GENE OF STREPTOMYCES-COELICOLOR A3(2) - A REGULATORY GENE INVOLVED IN MORPHOGENESIS AND ANTIBIOTIC PRODUCTION

Citation
M. Elliot et al., THE BLDD GENE OF STREPTOMYCES-COELICOLOR A3(2) - A REGULATORY GENE INVOLVED IN MORPHOGENESIS AND ANTIBIOTIC PRODUCTION, Journal of bacteriology, 180(6), 1998, pp. 1549-1555
Citations number
46
Categorie Soggetti
Microbiology
Journal title
ISSN journal
00219193
Volume
180
Issue
6
Year of publication
1998
Pages
1549 - 1555
Database
ISI
SICI code
0021-9193(1998)180:6<1549:TBGOSA>2.0.ZU;2-4
Abstract
The bid mutants of Streptomyces coelicolor A3(2) are blocked at the ea rliest stage of sporulation, the formation of aerial hyphae, and are p leiotropically defective in antibiotic production. Using a phage libra ry of wild-type S. coelicolor DNA, se isolated a recombinant phage whi ch restored both sporulation and antibiotic production to strains carr ying the single known bldD mutation. Nucleotide sequence analysis of a 1.3-kb complementing subclone identified an open reading frame, desig nated bldD, encoding a translation product of 167 amino acid residues. Nucleotide sequence analysis of the bldD-containing fragment amplifie d from the chromosome of a bldD mutant strain revealed a point mutatio n changing a tyrosine residue at amino acid position 62 to a cysteine. Although a comparison of the BldD sequence to known proteins in the d atabases failed to show any strong similarities, analysis of the BldD sequence for secondary structural elements did reveal a putative helix -turn-helix, DNA recognition element near the C terminus of the protei n. A comparison of bldD transcript levels in the bldD(+) and bldD muta nt strains using both Northern blot analysis and SI nuclease protectio n studies showed vast overexpression of bldD transcripts in the mutant , suggesting that BldD negatively regulates its own synthesis. High-re solution S1 nuclease mapping identified the transcription start point as a G residue 63 nucleotides upstream from the bldD start codon and 7 nucleotides downstream from -10 and -35 sequences resembling E. coli- like streptomycete promoters.