title: Ribonuclease D is not essential for the normal growth of Escherichia coli or bacteriophage T4 or for the biosynthesis of a T4 suppressor tRNA.
abstract: Transposon Tn10-mediated rearrangement was used to isolate a strain of Escherichia coli carrying a deletion in the rnd region which is known to encode the structural gene for the putative 3' tRNA processing nuclease, RNase D. Genetic analysis indicated that about 0.4-0.5 min of the chromosome in the 39.5-40.0 min region was deleted. The mutant strain was devoid of RNase D activity, but other RNase activities were unaffected. The viability of the mutant strain and its normal growth characteristics indicate that RNase D is not essential for E. coli survival. The normal plating efficiency in this mutant host of wild type T4 and a T4 psu1+-amber double mutant indicates that RNase D is also not required for T4 growth or psu1+-tRNA processing. The implications of these findings for the role of RNase D in bacterial and bacteriophage tRNA metabolism, and the possible involvement of alternative enzymes, are discussed.
mesh_terms: D004722:Endoribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D029968:Escherichia coli Proteins; D007700:Kinetics; D012343:RNA, Transfer / Q000235:genetics*; D043244:Ribonuclease III; D013045:Species Specificity; D013604:T-Phages / Q000201:enzymology* / Q000235:genetics; D014779:Virus Replication
chemical_list: D029968:Escherichia coli Proteins; D012343:RNA, Transfer; D004722:Endoribonucleases; D043244:Ribonuclease III; C468366:ribonuclease III, E coli