title: Occurrence of 1-methyladenosine and absence of ribothymidine in transfer ribonucleic acid of Mycobacterium smegmatis.
abstract: The minor base composition of Mycobacterium smegmatis tRNA has been studied. Thin-layer chromatographic patterns of a ribonuclease T2 digest of mycobacterial tRNA indicated the presence of appreciable amounts of 1-methyladenosine (which is commonly present only in eucaryotic tRNA), dihydrouridine, and 7-methylguanosine. Ribothymidine was absent. The S-adenosylmethionine-dependent tRNA methylases of M. smegmatis catalyzed the formation of 1-methyladenosine when Escherichia coli tRNA was used as acceptor. Similarly, E. coli extracts methylated the tRNA of M. smegmatis, forming ribothymidine.
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000032:analysis; D004926:Escherichia coli / Q000032:analysis; D008745:Methylation; D009161:Mycobacterium / Q000032:analysis* / Q000201:enzymology; D012329:RNA, Bacterial / Q000032:analysis*; D012343:RNA, Transfer / Q000032:analysis*; D013045:Species Specificity; D013936:Thymidine / Q000031:analogs & derivatives* / Q000032:analysis; D012359:tRNA Methyltransferases / Q000378:metabolism
chemical_list: D012329:RNA, Bacterial; D012343:RNA, Transfer; D012359:tRNA Methyltransferases; D000241:Adenosine; D013936:Thymidine