Lys70 of E. coli quinolinate phosphoribosyltransferase is protected from chemical modification by formation of an inhibitor complex.
Quinolinate phosphoribosyltransferase was examined for susceptibility to different chemical modification reagents. Loss of enzyme activity with trinitrobenzenesulfonate (TNBS) occurred when 1.1 lysines per subunit were modified. Tryptic digestion of the modified enzyme followed by HPLC-MS analysis of the peptides showed Lys70 reacts with TNBS. Based on x-ray studies, this amino acid participates in a conformational change distant from the active site.
Department of Chemistry, University of Akron, Akron, OH 44325-3601, USA.
Rajula
R
Gaur
Tanesha
T
Roberts
Kim
K
Calvo
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D017124:Conserved Sequence; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D004926:Escherichia coli / Q000201:enzymology*; D008239:Lysine / Q000737:chemistry* / Q000378:metabolism; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010430:Pentosyltransferases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism*; D016415:Sequence Alignment; D000098553:Nicotinate-Nucleotide Diphosphorylase (Carboxylating)
D004791:Enzyme Inhibitors; D010430:Pentosyltransferases; D000098553:Nicotinate-Nucleotide Diphosphorylase (Carboxylating); D008239:Lysine