GENE ORGANIZATION IN THE TRXA B-ORIC REGION OF THE STREPTOMYCES-COELICOLOR CHROMOSOME AND COMPARISON WITH OTHER EUBACTERIA/

The gene organization was determined in the trxA/B-rnpA region of the Streptomyces coelocolor chromosome, near to the origin of replication, oriC. Previously, we showed that the trxA and trxB genes, coding for thioredoxin and thioredoxin reductase, respectively, occur in S. coeli color as a gene cluster and are contained on a cosmid H24 that carries oriC and several genes involved in DNA replication. Here we show that the trxA/B locus is positioned approx. 9.4 kb from oriC, present the nucleotide sequence of the trxA/B-rnpA region and use sequence analysi s to identify the nature of the intervening genes. Seven open reading frames were found, all oriented in the same direction, five of which w ere identified as the S. coelicolor homologs of SpoIIIJ, Jag, GidB, So j and SpoOJ in Bacillus subtilis and which have been ascribed differen t functions in this and other bacteria for either DNA replication, chr omosomal partitioning or morphological development. The arrangement of the genes coding for the above five proteins in the trxA/B-rnpA regio n in S. coelicolor resembles that in Mycobacterium leprae, Mycobacteri um tuberculosis, B. subtilis and Pseudomonas putida, and supports the view that many of the genes necessary for development and cell divisio n in bacteria are organized in a similar fashion. In B. subtilis and P . putida, however, the trxA/B genes are not present in the above gene arrangement. (C) 1998 Elsevier Science B.V. All rights reserved.