The active sites of the beta-lactamases of Streptomyces cacaoi and Streptomyces albus G.
The active-site serine of the extracellular beta-lactamases of Streptomyces cacaoi and Streptomyces albus G has been labelled with beta-iodopenicillanate. The determination of the sequence of the labelled peptides obtained after trypsin digestion of the denatured proteins indicate both enzymes to be class A beta-lactamases. Surprisingly the two Streptomyces enzymes do not appear to be especially homologous, and none of them exhibited a high degree of homology with the Streptomyces R61 DD-peptidase. Our data confirm that, as a family of homologous enzymes, class A is rather heterogeneous, with only a small number of conserved residues in all members of the class.
De Meester
F
F
Laboratoires de Microbiologie et d'Enzymologie, Université de Liège, Belgium.
Joris
B
B
Lenzini
M V
MV
Dehottay
P
P
Erpicium
T
T
Dusart
J
J
Klein
D
D
Ghuysen
J M
JM
Frère
J M
JM
Van Beeumen
J
J
D000595:Amino Acid Sequence; D001665:Binding Sites; D002852:Chromatography, Ion Exchange; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D008623:Mercaptoethanol / Q000494:pharmacology; D010397:Penicillanic Acid / Q000494:pharmacology / Q000031:analogs & derivatives; D010446:Peptide Fragments / Q000302:isolation & purification; D013056:Spectrophotometry, Ultraviolet; D013302:Streptomyces / Q000201:enzymology*; D001618:beta-Lactamases / Q000378:metabolism*
D010446:Peptide Fragments; D008623:Mercaptoethanol; D010397:Penicillanic Acid; D004228:Dithionitrobenzoic Acid; C031528:6-iodopenicillanic acid; D001618:beta-Lactamases