Disease relevance of hemT

• In Rhodobacter sphaeroides 2.4.1, the cellular requirements for 5-aminolevulinic acid (ALA) are in part regulated by the level of ALA synthase activity, which is encoded by the hemA and hemT genes [1].
• On the other hand, the hemT gene from mutant H-5 was able to complement an E. coli mutant requiring ALA for growth [2].
• The 5-aminolevulinate synthase gene (hemA) from Rhizobium meliloti was used to probe a genomic lambda bank derived from Rhodobacter sphaeroides DNA [3].
• 5-Aminolevulinate synthase of Rhodopseudomonas spheroides interacts with its cofactor, pyridoxal phosphate, and shows an absorption maximum at 430 nm with a probable shoulder at 320--330 nm [4].

High impact information on hemT

• ALA synthase activity is encoded by two differentially regulated genes in R. sphaeroides 2.4.1: hemA and hemT [5].
• The nucleotide sequences of the Rhodobacter sphaeroides hemA and hemT genes, encoding 5-aminolevulinic acid (ALA) synthase isozymes, were determined [6].
• 5-Aminolevulinic acid availability and control of spectral complex formation in hemA and hemT mutants of Rhodobacter sphaeroides [7].
• The rdxA and hemT genes may share a transcriptional regulatory region [8].
• The rdxA gene was localized to the smaller of two R. sphaeroides chromosomes, upstream of and divergently transcribed from hemT, which encodes one of two 5-aminolevulinate synthase isozymes [8].

Biological context of hemT

• These chromosomal disruption allowed hemA and hemT to be precisely localized on the larger and smaller of two R. sphaeroides chromosomes, respectively [7].
• The Rhodobacter capsulatus hemA gene, coding for the enzyme delta-aminolevulinic acid synthase (ALAS), was isolated from a genome bank by hybridization with a hemT probe from Rhodobacter sphaeroides [9].

Associations of hemT with chemical compounds

• The hemA and hemT genes encode isozymes that catalyze the formation of 5-aminolevulinic acid, the first step in the biosynthesis of all tetrapyrroles present in R. sphaeroides 2.4 [10].
• Mode of binding of pyridoxal phosphate to 5-aminolevulinate synthase [4].

Other interactions of hemT

• Additionally, genes for glyceraldehyde 3-phosphate dehydrogenase (gapB) and delta-aminolevulinic acid synthase (hemT) are found on chromosome II [11].

References