|PROSITE documentation PDOC00608 [for PROSITE entry PS00747]|
Delta-aminolevulinic acid (ALA) is the obligatory precursor for the synthesis of all tetrapyrroles including porphyrin derivatives such as chlorophyll and heme. ALA can be synthesized via two different pathways: the Shemin (or C4) pathway which involves the single step condensation of succinyl-CoA and glycine and which is catalyzed by ALA synthase (EC 126.96.36.199) and via the C5 pathway from the five-carbon skeleton of glutamate. The C5 pathway operates in the chloroplast of plants and algae, in cyanobacteria, in some eubacteria and in archaebacteria.
The initial step in the C5 pathway is carried out by glutamyl-tRNA reductase (GluTR)  which catalyzes the NADP-dependent conversion of glutamate-tRNA(Glu) to glutamate-1-semialdehyde (GSA) with the concomitant release of tRNA(Glu) which can then be recharged with glutamate by glutamyl-tRNA synthetase.
GluTR is a protein of about 50 Kd (467 to 550 residues) which contains a few conserved region. The best conserved region is located in positions 99 to 122 in the sequence of known GluTR. This region seems important for the activity of the enzyme. We have developed a signature pattern from that conserved region.Last update:
April 2006 / Pattern revised.
PROSITE method (with tools and information) covered by this documentation:
|1||Authors||Jahn D., Verkamp E., Soell D.|
|Title||Glutamyl-transfer RNA: a precursor of heme and chlorophyll biosynthesis.|
|Source||Trends Biochem. Sci. 17:215-218(1992).|