tRNA accumulation and suppression of the bldA phenotype during development in Streptomyces coelicolor.
Streptomyces coelicolor undergoes distinct morphological changes as it grows on solid media where spores differentiate into vegetative and aerial mycelium that is followed by the production of spores. Deletion of bldA, encoding the rare tRNA(Leu) UAA, blocks development at the stage of vegetative mycelium formation. From previous data it appears that tRNA(Leu) UAA accumulates relatively late during growth while two other tRNAs do not. Here, we studied the expression of 17 different tRNAs including bldA tRNA, and the RNA subunit of the tRNA processing endoribonuclease RNase P. Our results showed that all selected tRNAs and RNase P RNA increased with time during development. However, accumulation of bldA tRNA and another rare tRNA(Leu) isoacceptor started at an earlier stage compared with the other tRNAs. We also introduced the bldA tRNA anticodon (UAA) into other tRNAs and introduced these into a bldA deletion strain. In particular, one such mutant tRNA derived from the tRNA(Leu) CAA isoacceptor suppressed the bldA phenotype. Thus, the bldA tRNA scaffold is not critical for function as a regulator of S. coelicolor cell differentiation. Further substitution experiments, in which the 5'- and 3'-flanking regions of the suppressor tRNA were changed, indicated that these regions were important for the suppression.
Department of Cell and Molecular Biology, Box 596, Biomedical Centre, SE-751 24 Uppsala, Sweden.
B M Fredrik
BM
Pettersson
Leif A
LA
Kirsebom
D001483:Base Sequence; D015536:Down-Regulation; D015964:Gene Expression Regulation, Bacterial; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010641:Phenotype; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism*; D012356:RNA, Transfer, Leu / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D048372:Streptomyces coelicolor / Q000737:chemistry / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*
C107344:BldA tRNA, Streptomyces coelicolor; D012329:RNA, Bacterial; D012356:RNA, Transfer, Leu; D012343:RNA, Transfer