Deletions fusing the hisG and hisD genes in Salmonella typhimurium.
Frameshift mutation hisD497 occurs in the operator-proximal portion of the Salmonella typhimurium gene coding for the dimeric protein, L-histidinol dehydrogenase (HDH). Rare revertants of hisD497 are deletions fusing the hisD gene to the adjacent preceding structural gene, hisG (adenosine 5'-triphosphate-PR transferase). HDH purified from one revertant, hisGD4908, contains subunits of approximately normal molecular weight but with no clearly demonstrable unique amino-terminal sequence. We propose that a combined inactive G-D polypeptide is synthesized and then cleaved at a number of closely juxtaposed sites by endoproteolytic activity. At least some of the resulting fragments then participate in formation of active HDH dimers.
D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial / Q000032:analysis; D005796:Genes; D006639:Histidine / Q000378:metabolism; D006641:Histidinol; D008954:Models, Biological; D009154:Mutation; D009876:Operon; D010088:Oxidoreductases / Q000032:analysis / Q000096:biosynthesis; D010455:Peptides / Q000032:analysis; D012483:Salmonella Phages; D012486:Salmonella typhimurium / Q000201:enzymology / Q000378:metabolism*; D014161:Transduction, Genetic
D010455:Peptides; D006639:Histidine; D006641:Histidinol; D010088:Oxidoreductases