type	Journal Article
authors	Mills, D. A.; Flickinger, M. C.
title	Cloning and sequence analysis of the meso-diaminopimelate decarboxylase gene from Bacillus methanolicus MGA3 and comparison to other decarboxylase genes
journal	Appl Environ Microbiol
Activity	4.1.1.20
Family	4.1.1.20
sel	selected
ui	8215365
year	(1993)
volume	59
number	9
pages	2927-37
keywords	Amino Acid Sequence
abstract	The lysA gene of Bacillus methanolicus MGA3 was cloned by complementation of an auxotrophic Escherichia coli lysA22 mutant with a genomic library of B. methanolicus MGA3 chromosomal DNA. Subcloning localized the B. methanolicus MGA3 lysA gene into a 2.3-kb SmaI-SstI fragment. Sequence analysis of the 2.3-kb fragment indicated an open reading frame encoding a protein of 48,223 Da, which was similar to the meso-diaminopimelate (DAP) decarboxylase amino acid sequences of Bacillus subtilis (62%) and Corynebacterium glutamicum (40%). Amino acid sequence analysis indicated several regions of conservation among bacterial DAP decarboxylases, eukaryotic ornithine decarboxylases, and arginine decarboxylases, suggesting a common structural arrangement for positioning of substrate and the cofactor pyridoxal 5'-phosphate. The B. methanolicus MGA3 DAP decarboxylase was shown to be a dimer (M(r) 86,000) with a subunit molecular mass of approximately 50,000 Da. This decarboxylase is inhibited by lysine (Ki = 0.93 mM) with a Km of 0.8 mM for DAP. The inhibition pattern suggests that the activity of this enzyme in lysine-overproducing strains of B. methanolicus MGA3 may limit lysine synthesis.
last changed	2009/06/08 14:26