Phosphoribosylanthranilate isomerase: Difference between revisions
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:N-(5-phospho-beta-D-ribosyl)anthranilate <math>\rightleftharpoons</math> 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate |
:N-(5-phospho-beta-D-ribosyl)anthranilate <math>\rightleftharpoons</math> 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate |
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[[PRAI Structure|3D Rendering of Phosphoribosylanthranilate Isomerase]] |
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In other words, this enzyme has one [[substrate (biochemistry)|substrate]], N-(5-phospho-beta-D-ribosyl)anthranilate, and one [[product (chemistry)|product]], 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate. |
In other words, this enzyme has one [[substrate (biochemistry)|substrate]], N-(5-phospho-beta-D-ribosyl)anthranilate, and one [[product (chemistry)|product]], 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate. |
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Revision as of 13:56, 26 September 2013
| phosphoribosylanthranilate isomerase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 5.3.1.24 | ||||||||
| CAS no. | 37259-82-8 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
| PRAI | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 crystal structure of mutually generated monomers of dimeric phosphoribosylantranilate isomerase from Thermotoga maritima | |||||||||
| Identifiers | |||||||||
| Symbol | PRAI | ||||||||
| Pfam | PF00697 | ||||||||
| Pfam clan | CL0036 | ||||||||
| InterPro | IPR001240 | ||||||||
| SCOP2 | 1pii / SCOPe / SUPFAM | ||||||||
| |||||||||
In enzymology, a phosphoribosylanthranilate isomerase (EC 5.3.1.24) is an enzyme that catalyzes the third step of tryptophan biosynthesis.[1]
This enzyme participates in the phenylalanine, tyrosine and tryptophan biosynthesis pathway.
In yeast it is encoded by the TRP1 gene.[2]
Reaction
- N-(5-phospho-beta-D-ribosyl)anthranilate 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate
In other words, this enzyme has one substrate, N-(5-phospho-beta-D-ribosyl)anthranilate, and one product, 1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate.
Nomenclature
This enzyme belongs to the family of isomerases, specifically those intramolecular oxidoreductases interconverting aldoses and ketoses. The systematic name of this enzyme class is N-(5-phospho-beta-D-ribosyl)anthranilate aldose-ketose-isomerase. Other names in common use include:
- PRA isomerase,
- PRAI,
- IGPS:PRAI (indole-3-glycerol-phosphate,
- synthetase/N-5'-phosphoribosylanthranilate isomerase complex), and
- N-(5-phospho-beta-D-ribosyl)anthranilate ketol-isomerase.
Structural
Phosphoribosylanthranilate isomerase (PRAI) is monomeric and labile in most mesophilic microorganisms, but dimeric and stable in the hyperthermophile Thermotoga maritima (tPRAI).[3] The comparison to the known 2.0 A structure of PRAI from Escherichia coli (ePRAI) shows that tPRAI has a TIM-barrel fold, whereas helix alpha5 in ePRAI is replaced by a loop. The subunits of tPRAI associate via the N-terminal faces of their central beta-barrels. Two long, symmetry-related loops that protrude reciprocally into cavities of the other subunit provide for multiple hydrophobic interactions. Moreover, the side chains of the N-terminal methionines and the C-terminal leucines of both subunits are immobilized in a hydrophobic cluster, and the number of salt bridges is increased in tPRAI. These features appear to be mainly responsible for the high thermostability of tPRAI.[4]
References
- ^ Creighton TE, Yanofsky C (1970). "Chorismate to tryptophan (Escherichia coli) - Anthranilate synthetase, PR transferase, PRA isomerase, InGP synthetase, tryptophan synthetase". Methods Enzymol. 17A: 365–380.
- ^ "TRP1/YDR007W Summary". Saccharomyces genome database. Stanford University.
- ^ Thoma R, Hennig M, Sterner R, Kirschner K (2000). "Structure and function of mutationally generated monomers of dimeric phosphoribosylanthranilate isomerase from Thermotoga maritima". Structure. 8 (3): 265–76. PMID 10745009.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ Hennig M, Sterner R, Kirschner K, Jansonius JN (1997). "Crystal structure at 2.0 A resolution of phosphoribosyl anthranilate isomerase from the hyperthermophile Thermotoga maritima: possible determinants of protein stability". Biochemistry. 36 (20): 6009–16. doi:10.1021/bi962718q. PMID 9166771.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link)
Further reading
- Braus GH, Luger K, Paravicini G, Schmidheini T, Kirschner K, Hütter R (1988). "The role of the TRP1 gene in yeast tryptophan biosynthesis". J. Biol. Chem. 263 (16): 7868–75. PMID 3286643.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link)