Open AccessPrimary structure of the Streptomyces R61 extracellular DD‐peptidase
Author(s) -
DUEZ Colette,
PIRONFRAIPONT Claudine,
JORIS Bernard,
DUSART Jean,
URDEA Mickey S.,
MARTIAL Joseph A.,
FRÈRE JeanMarie,
GHUYSEN JeanMarie
Publication year - 1987
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1987.tb10669.x
Subject(s) - biology , protein primary structure , nucleic acid sequence , peptide sequence , biochemistry , microbiology and biotechnology , streptomyces , structural gene , gene , amino acid , serine , escherichia coli , genetics , enzyme , bacteria
An 11450‐base DNA fragment containing the gene for the extracellular active‐site serine DD‐peptidase of Streptomyces R61 was cloned in Streptomyces lividans using the high‐copy‐number plasmid pIJ702 as vector. Amplified expression of the excreted enzyme was observed. Producing clones were identified with the help of a specific antiserum directed against the pure DD‐peptidase. The coding sequence of the gene was then located by hybridization with a specific nucleotide probe and sub‐fragments were obtained from which the nucleotide sequence of the structural gene and the putative promoter and terminator regions were determined. The sequence suggests that the gene codes for a 406‐amino‐acid protein precursor. When compared with the excreted, mature DD‐peptidase, this precursor possesses a cleavable 31‐amino‐acid N‐terminal extension which has the characteristics of a signal peptide, and a cleavable 26‐amino‐acid C‐terminal extension. On the basis of the data of Joris et al. (following paper in this journal), the open reading frame coding for the synthesis of the DD‐peptidase was established. Comparison of the primary structure of the Streptomyces R61 DD‐peptidase with those of several active‐site serine β‐lactamases and penicillin‐binding proteins of Escherichia coli shows homology in those sequences that comprise the active‐site serine residue. When the comparison is broadened to the complete amino acid sequences, significant homology is observed only for the pair Streptomyces R61 DD‐peptidase/ Escherichia coli amp C β‐lactamase (class C). Since the Streptomyces R61 DD‐peptidase and β‐lactamases of class A have very similar three‐dimensional structures [Kelly et al. (1986) Science (Wash. DC) 231 , 1429–1431; Samraoui et al. (1986) Nature (Lond.) 320 , 378–380], it is concluded that these tertiary features are probably also shared by the β‐lactamases of class C, i.e. that the Streptomyces R61 DD‐peptidase and the β‐lactamases of classes A and C are related in an evolutionary sense.