Summary: A 3·4 kb RI fragment, cloned in , that carries part of a cluster of genes encoding arginine biosynthetic functions of the thermophilic bacterium , was sequenced on both strands. The sequence consists of a truncated gene, an region encoding a polypeptide with both -acetylglutamate synthase and ornithine acetyltransferase activities, the gene and the -terminal part of . The gene encodes a 258-amino-acid polypeptide with a deduced of 26918. A very high and thermostable -acetylglutamate 5-phosphotransferase activity was detected in extracts of mutants transformed with the 3·4 kb fragment on a plasmid. A polypeptide band of 27000 was detected by SDS-PAGE of heat-treated extract from such a strain. Both -acetylglutamate synthase and ornithine acetyltransferase are encoded by the same 1290 bp open reading frame. The deduced sequence of 410 amino acids corresponds to a peptide of 43349. The subcloned can complement a double mutant to prototrophy. Gel-filtration of a heat-treated extract of the complemented double mutant host showed that -acetylglutamate synthase and ornithine acetyltransferase activities co-elute in a single peak corresponding to 110000. Both activities were also heat-inactivated at the same temperature and strongly inhibited by ornithine. These results suggest that both activities can be ascribed to a single protein.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error