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Crystal structure of the bifunctional protein PriaCrystal structure of the bifunctional protein Pria
Structural highlights
FunctionHIS4_STRCO Catalyzes the isomerization of the aminoaldose moiety of ProFAR to the aminoketose of PRFAR in the biosynthesis pathway for histidine and the isomerization of the aminoaldose PRA to the aminoketose CdRP in the biosynthsis pathway for tryptophan.[HAMAP-Rule:MF_01014] Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedSome bacterial genomes contain an incomplete set of genes encoding phosphoribosyl isomerases, raising the question of whether there exists broadened substrate specificity for the missing gene products. To investigate the underlying molecular principles of this hypothesis, we have determined the crystal structure of the bifunctional enzyme PriA from Streptomyces coelicolor at 1.8 A resolution. It consists of a (betaalpha)(8)-barrel fold that is assembled by two symmetric (betaalpha)(4) half-barrels. The structure shows how its active site may catalyse the isomerization reactions of two different substrates, and we provide a plausible model of how the smaller of the two substrates could be bound in two different orientations. Our findings expand the half-barrel ancestor concept by demonstrating that symmetry-related half-barrels could provide a smart solution to cope with dual substrate specificity. The data may help to unravel molecular rationales regarding how organisms with miniature genomes can keep central biological pathways functional. Two-fold repeated (betaalpha)4 half-barrels may provide a molecular tool for dual substrate specificity.,Kuper J, Doenges C, Wilmanns M EMBO Rep. 2005 Feb;6(2):134-9. PMID:15654319[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References |
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