Cloned (Comment) | Organism |
---|---|
gene HEMA1 | Arabidopsis thaliana |
Crystallization (Comment) | Organism |
---|---|
purified recombinant GluTR in ternary complex with GBP and FLUTPR, the protein are mixed at molar ratio of 2:3:3, X-ray diffraction structure determination and analysis at 3.2 A resolution, molecular replacement method | Arabidopsis thaliana |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
heme | feedback inhibition | Arabidopsis thaliana | |
additional information | structure analysis of the FLUTPR-GluTR-GBP ternary complex, overview. Three mechanisms for plant GluTR activity regulation: (i) the end-product feedback inhibition by heme, (ii) repression by a membrane protein FLUORESCENT (FLU), and (iii) formation of complex with a soluble GluTR-binding protein (GBP) | Arabidopsis thaliana | |
protein FLU | membrane protein FLUORESCENT, protein FLU directly interacts with GluTR's dimerization domain through its tetratricopepetide-repeat (TPR) domain. Enzyme binding structure, overview | Arabidopsis thaliana | |
protein GBP | a soluble GluTR-binding protein, enzyme binding structure, overview. the GluTR-GBP complex is stable and has a low apparent dissociation constant. Protein GBP is initially found in chloroplast stroma | Arabidopsis thaliana |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-glutamyl-tRNAGlu + NADPH + H+ | Arabidopsis thaliana | - |
L-glutamate 1-semialdehyde + NADP+ + tRNAGlu | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | P42804 | - |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-glutamyl-tRNAGlu + NADPH + H+ | - |
Arabidopsis thaliana | L-glutamate 1-semialdehyde + NADP+ + tRNAGlu | - |
? |
Subunits | Comment | Organism |
---|---|---|
More | GluTR consists of three domains: an N-terminal catalytic domain, an NADPH-binding domain, and a C-terminal dimerization domain | Arabidopsis thaliana |
Synonyms | Comment | Organism |
---|---|---|
GluTR | - |
Arabidopsis thaliana |
HEMA1 | - |
Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NADP+ | - |
Arabidopsis thaliana | |
NADPH | - |
Arabidopsis thaliana |
Organism | Comment | Expression |
---|---|---|
Arabidopsis thaliana | expression of HEMA1 that encodes the dominant GluTR in the photosynthetic tissues is regulated by light | up |
General Information | Comment | Organism |
---|---|---|
metabolism | plants synthesize delta-aminolevulenic acid (ALA), the precursor for all tetrapyrrole molecules, from glutamate via a three-step pathway1 The first step is ligation of glutamate to tRNAGlu catalyzed by glutamyl-tRNA synthetase. Then glutamyl-tRNA reductase (GluTR) reduces the tRNAGlu-bound glutamate to glutamate-1-semialdehyde (GSA) in an NADPH-dependent manner. GSA is subsequently isomerized to ALA by a vitamin B6-dependent enzyme, glutamate-1-semialdehyde aminomutase (GSAM). 5-Aminolevulinic acid synthesis is the key regulatory point for the entire tetrapyrrole biosynthetic pathway, and particularly GluTR is subjected to a tight control at the post-translational level | Arabidopsis thaliana |
additional information | three mechanisms for plant GluTR activity regulation: (i) the end-product feedback inhibition by heme, (ii) repression by a membrane protein FLUORESCENT (FLU), and (iii) formation of complex with a soluble GluTR-binding protein (GBP) | Arabidopsis thaliana |
physiological function | the GluTR-catalyzed glutamyl-tRNAGlu reduction by NADPH is a key regulatory point of the tetrapyrrole biosynthetic pathway. Plants synthesize delta-aminolevulenic acid (ALA), the precursor for all tetrapyrrole molecules, from glutamate via a three-step pathway. The first step is ligation of glutamate to tRNAGlu catalyzed by glutamyl-tRNA synthetase. Then glutamyl-tRNA reductase (GluTR) reduces the tRNAGlu-bound glutamate to glutamate-1-semialdehyde (GSA) in an NADPH-dependent manner. GSA is subsequently isomerized to 5-aminolevulinic acid by a vitamin B6-dependent enzyme, glutamate-1-semialdehyde aminomutase (GSAM). 5-Aminolevulinic acid synthesis is the key regulatory point for the entire tetrapyrrole biosynthetic pathway, and particularly GluTR is subjected to a tight control at the post-translational level. Regulation of the enzyme within the pathway, detailed overview. Glutamate-1-semialdehyde aminomutase (GSAM) is proposed to form complex with GluTR to enable GSA channeling from GluTR to GSAM in bacteria, but not in plants | Arabidopsis thaliana |