8hx6

Crystal structure of 4-amino-4-deoxychorismate synthase from Streptomyces venezuelae

spinqualitylabelsall models 8hx6, resolution 2.14Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 8hx6 is a 2 chain structure with sequence from Streptomyces venezuelae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.14Å Ligands: MG, MLT, OCS, SIN, TRP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q6L8Q5_STRVZ Publication Abstract from PubMed 4-Amino-4-deoxychorismate synthase (ADCS), a chorismate-utilizing enzyme, is composed of two subunits: PabA and PabB. PabA is a glutamine amidotransferase that hydrolyzes glutamine into glutamate and ammonia. PabB is an aminodeoxychorismate synthase that converts chorismate to 4-amino-4-deoxychorismate (ADC) using the ammonia produced by PabA. ADCS functions under allosteric regulation between PabA and PabB. However, the allosteric mechanism remains unresolved because the structure of the PabA-PabB complex has not been determined. Here, the crystal structure and characterization of PapA from Streptomyces venezuelae (SvPapA), a bifunctional enzyme comprising the PabA and PabB domains, is reported. SvPapA forms a unique dimer in which PabA and PabB domains from different monomers complement each other and form an active structure. The chorismate-bound structure revealed that recognition of the C1 carboxyl group by Thr501 and Gly502 of the 498-PIKTG-502 motif in the PabB domain is essential for the catalytic Lys500 to reach the C2 atom, a reaction-initiation site. SvPapA demonstrated ADCS activity in the presence of Mg(2+) when glutamate or NH(+)(4) was used as the amino donor. The crystal structure indicated that the Mg(2+)-binding position changed depending on the binding of chorismate. In addition, significant structural changes were observed in the PabA domain depending on the presence or absence of chorismate. This study provides insights into the structural factors that are involved in the allosteric regulation of ADCS. Structural basis for the allosteric pathway of 4-amino-4-deoxychorismate synthase.,Nakamichi Y, Kobayashi J, Toyoda K, Suda M, Hiraga K, Inui M, Watanabe M Acta Crystallogr D Struct Biol. 2023 Oct 1;79(Pt 10):895-908. doi: , 10.1107/S2059798323006320. Epub 2023 Sep 15. PMID:37712435 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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