J. Biol. Chem., Vol. 261, Issue 23, 10632-10636, 08, 1986
Nucleotide sequence of the purM gene encoding 5'-phosphoribosyl-5- aminoimidazole synthetase of Escherichia coli K12
JM Smith and HA Daum 3d
5'-Phosphoribosyl-5-aminoimidazole synthetase (EC 6.3.3.1), encoded by the
purM gene of Escherichia coli, catalyzes the synthesis of 5'-
phosphoribosyl-5-aminoimidazole from 5'- phosphoribosylformylglycinamidine.
The purM gene was subcloned from the Clarke and Carbon (Clarke, L., and
Carbon, J. (1976) Cell 9, 91-99) plasmid pLC1-41 and the nucleotide
sequence determined. The mature protein, as deduced from the purM
structural gene sequence, contains 344 amino acid residues and has a
calculated Mr of 36,726. The 5' end of the purM mRNA was determined by mung
bean nuclease mapping to be 44- 45 nucleotides up-stream of the proposed
GTG translation initiation codon. A C-G-rich region characteristic of
stringently controlled promoters is located immediately in front of the
proposed purM promoter region. Comparison of the upstream sequences of the
purM and the coregulated purF loci revealed a highly conserved (33 of 39
base pairs are identical) sequence. The presumptive purM promoter is
located in this region, thus suggesting that both purine loci share a
common mechanism of regulation mediated through this sequence.