Genetics of the serine cycle in Methylobacterium extorquens AM1: identification of sgaA and mtdA and sequences of sgaA, hprA, and mtdA.

Genetics of the serine cycle in Methylobacterium extorquens AM1: identification, sequence, and mutation of three new genes involved in C1 assimilation, orf4, mtkA, and mtkB.

In a recent paper we reported the sequence of the beginning of a serine cycle gene cluster on the Methylobacterium extorquens AM1 chromosome, containing the genes encoding serine glyoxylate aminotransferase (sgaA), hydroxypyruvate reductase (hprA), and 5,10-methylenetetrahydrofolate dehydrogenase (mtdA) (L. V. Chistoserdova and M. E. Lidstrom J. Bacteriol. 176:1957-1968, 1994). Here we present ...

Identification of sgaA and mtdA and Sequences of sgaA, hprA, and mtdA

QscR, a LysR-type transcriptional regulator and CbbR homolog, is involved in regulation of the serine cycle genes in Methylobacterium extorquens AM1.

A new gene, qscR, encoding a LysR-type transcriptional regulator that is a homolog of CbbR, has been characterized from the facultative methylotroph Methylobacterium extorquens AM1 and shown to be the major regulator of the serine cycle, the specific C1 assimilation pathway. The qscR mutant was shown to be unable to grow on C1 compounds, and it lacked the activity of serine-glyoxylate aminotran...

QscR-mediated transcriptional activation of serine cycle genes in Methylobacterium extorquens AM1.

QscR, a LysR-type regulator, is the major regulator of assimilatory C1 metabolism in Methylobacterium extorquens AM1. It has been shown to interact with the promoters of the two operons that encode the majority of the serine cycle enzymes (sga-hpr-mtdA-fch for the qsc1 operon and mtkA-mtkB-ppc-mclA for the qsc2 operon), as well as with the promoter of glyA and its own promoter. To obtain furthe...

Development of an insertional expression vector system for Methylobacterium extorquens AM1 and generation of null mutants lacking mtdA and/or fch.

Over the past few years, the genetic 'toolkit' available for use with Methylobacterium extorquens AM1 has expanded significantly. Here a further advance is presented and demonstrated, an insertional expression system that allows expression of genes from a stable, unmarked chromosomal locus. This system has been used to better understand the role of the tetrahydrofolate (H4F) pathway in methylot...