Two Active Forms of UDP-N-Acetylglucosamine Enolpyruvyl Transferase in Gram-Positive Bacteria
AUTOR(ES)
Du, Wensheng
FONTE
American Society for Microbiology
RESUMO
Gene sequences encoding the enzymes UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) from many bacterial sources were analyzed. It was shown that whereas gram-negative bacteria have only one murA gene, gram-positive bacteria have two distinct genes encoding these enzymes which have possibly arisen from gene duplication. The two murA genes of the gram-positive organism Streptococcus pneumoniae were studied further. Each of the murA genes was individually inactivated by allelic replacement. In each case, the organism was viable despite losing one of its murA genes. However, when attempts were made to construct a double-deletion strain, no mutants were obtained. This indicates that both genes encode active enzymes that can substitute for each other, but that the presence of a MurA function is essential to the organism. The two genes were further cloned and overexpressed, and the enzymes they encode were purified. Both enzymes catalyzed the transfer of enolpyruvate from phosphoenolpyruvate to UDP-N-acetylglucosamine, confirming they are both active UDP-N-acetylglucosamine enolpyruvyl transferases. The catalytic parameters of the two enzymes were similar, and they were both inhibited by the antibiotic fosfomycin.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=101887Documentos Relacionados
- Cloning and sequencing of Escherichia coli murZ and purification of its product, a UDP-N-acetylglucosamine enolpyruvyl transferase.
- In Vitro and In Vivo Functional Activity of Chlamydia MurA, a UDP-N-Acetylglucosamine Enolpyruvyl Transferase Involved in Peptidoglycan Synthesis and Fosfomycin Resistance
- Hyaluronan Molecular Weight Is Controlled by UDP-N-acetylglucosamine Concentration in Streptococcus zooepidemicus*
- Variations in UDP-N-acetylglucosamine and UDP-N-acetylmuramyl-pentapeptide pools in Escherichia coli after inhibition of protein synthesis.
- Purification, characterization and structural determination of UDP-N-acetylglucosamine pyrophosphorylase produced by Moniliophthora perniciosa