glpA

GlpA is a gene encoding a subunit of the anaerobic glycerol-3-phosphate dehydrogenase (GlpABC) complex found in many bacteria, including Escherichia coli. The enzyme oxidizes sn-glycerol-3-phosphate to dihydroxyacetone phosphate, transferring electrons to the quinone pool in the membrane under anaerobic conditions.

GlpA is part of a membrane-associated, multimeric complex. Along with GlpB and GlpC, it participates in electron transfer from glycerol-3-phosphate to the respiratory chain. The exact architecture and cofactors of GlpA vary among species, but the subunits work together to couple substrate oxidation to energy conservation.

Protein features: GlpA proteins are frequently annotated as iron-sulfur proteins and are predicted to contain iron-sulfur clusters that shuttle electrons within the complex. They are typically encoded in an operon with glpB and glpC and associated with the inner membrane.

Regulation and expression: The glpABC operon is generally induced under anaerobic conditions and in the presence of glycerol-3-phosphate. In Escherichia coli, regulation involves the FNR global regulator and other factors such as CRP; species-specific regulatory elements may differ.

Importance and research: Understanding GlpA contributes to knowledge of bacterial anaerobic respiration and glycerol metabolism. Mutations can affect growth on glycerol-3-phosphate and may be exploited in metabolic engineering or studied for insights into respiratory chain diversification.