Disease relevance of betA

• In the present report, we cloned and expressed in Escherichia coli the betA gene from the moderate halophile Halomonas elongata which codes for a hypothetical choline dehydrogenase [1].
• The estimated subunit size of 66 kDa, which corresponds with the native size, is close to that deduced from the gene sequence of the Escherichia coli betA gene, and preliminary N-terminal sequencing shows homology with this deduced sequence [2].
• Use of hydrophobic chromatography for purification of the membrane-located choline dehydrogenase from a Pseudomonas strain [2].

High impact information on betA

• We found that E. coli cells in which choline dehydrogenase (CDH) was replaced with spinach CMO accumulate betaine and complement the salt-sensitive phenotype of the CDH-deleted E. coli mutant [3].
• Choline dehydrogenase (EC 1.1.99.1) catalyzes the four-electron oxidation of choline to glycine-betaine via a betaine-aldehyde intermediate [1].
• The end product of the pathway, glycine betaine, was a corepressor of choline induction for fusions at the betA and betT loci [4].
• Mapping by P1 transduction, F' complementation, and deletion mutagenesis showed the betA gene to be located at 7.5 min in the argF-codAB region of the chromosome [5].
• Mutants blocked at the level of choline dehydrogenase were isolated by selection of strains which did not grow at elevated osmotic strength in the presence of choline but grew when supplemented with glycine betaine [5].

Chemical compound and disease context of betA

• An elite maize inbred line DH4866 was transformed with the betA gene from Escherichia coli encoding choline dehydrogenase (EC 1.1.99.1), a key enzyme in the biosynthesis of glycine betaine from choline [6].
• The bacterium Escherichia coli produces glycine betaine by a two-step pathway where choline dehydrogenase (CDH), encoded by betA, oxidizes choline to betaine aldehyde which is further oxidized to glycine betaine by the same enzyme [7].

References