Characterization of a bordetella pertussis diaminopimelate (DAP) biosynthesis locus identifies dapC, a novel gene coding for an N-succinyl-L,L-DAP aminotransferase. (1/2)
The functional complementation of two Escherichia coli strains defective in the succinylase pathway of meso-diaminopimelate (meso-DAP) biosynthesis with a Bordetella pertussis gene library resulted in the isolation of a putative dap operon containing three open reading frames (ORFs). In line with the successful complementation of the E. coli dapD and dapE mutants, the deduced amino acid sequences of two ORFs revealed significant sequence similarities with the DapD and DapE proteins of E. coli and many other bacteria which exhibit tetrahydrodipicolinate succinylase and N-succinyl-L,L-DAP desuccinylase activity, respectively. The first ORF within the operon showed significant sequence similarities with transaminases and contains the characteristic pyridoxal-5'-phosphate binding motif. Enzymatic studies revealed that this ORF encodes a protein with N-succinyl-L,L-DAP aminotransferase activity converting N-succinyl-2-amino-6-ketopimelate, the product of the succinylase DapD, to N-succinyl-L,L-DAP, the substrate of the desuccinylase DapE. Therefore, this gene appears to encode the DapC protein of B. pertussis. Apart from the pyridoxal-5'-phosphate binding motif, the DapC protein does not show further amino acid sequence similarities with the only other known enzyme with N-succinyl-L,L-DAP aminotransferase activity, ArgD of E. coli. (+info)Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of DapC (Rv0858c) from Mycobacterium tuberculosis. (2/2)
N-Succinyldiaminopimelate aminotransferase from Mycobacterium tuberculosis (DAP-AT; DapC; Rv0858c) has been cloned, heterologously expressed in Escherichia coli, purified using standard chromatographic techniques and crystallized in two related crystal forms. Preliminary diffraction data analysis suggests the presence of a monomer in the asymmetric unit of the tetragonal crystal form and a dimer in the asymmetric unit of the orthorhombic crystal form. (+info)Succinyldiaminopimelate transaminase (SDP transaminase) is not a widely recognized or used term in medicine or clinical laboratory science. However, based on its name and the biochemical function implied by "transaminase," it can be inferred that this enzyme is likely involved in the transfer of an amino group from an amino donor to a succinylated diamino pimelic acid molecule during the biosynthesis of certain amino acids, such as lysine or meso-diaminopimelate.
Transaminases are enzymes that catalyze the transfer of an amino group (-NH2) from an α-amino acid to an α-keto acid, thus transforming one molecule into another while also reversibly converting the other molecule into a new amino acid. This reaction is crucial for the intermediary metabolism of amino acids in living organisms.
However, SDP transaminase is not a standard clinical laboratory test and does not have an established medical definition or reference range. It may be a term used in research or biochemistry contexts but is not typically encountered in medical practice or patient care.