6rxf

Crystal Structure of Bifidobacterium longum Multiple Inositol Polyphosphate Phosphatase Phosphohistidine Intermediate

spinqualitylabelsall models 6rxf, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 6rxf is a 2 chain structure with sequence from Bifidobacterium longum subsp. infantis ATCC 15697 = JCM 1222 = DSM 20088. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.397Å Ligands: NEP, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function B7GTV0_BIFLS Publication Abstract from PubMed Highly engineered phytases, which sequentially hydrolyze the hexakisphosphate ester of inositol known as phytic acid, are routinely added to the feeds of monogastric animals to improve phosphate bioavailability. New phytases are sought as starting points to further optimize the rate and extent of dephosphorylation of phytate in the animal digestive tract. Multiple inositol polyphosphate phosphatases (MINPPs) are clade 2 histidine phosphatases (HP2P) able to carry out the stepwise hydrolysis of phytate. MINPPs are not restricted by a strong positional specificity making them attractive targets for development as feed enzymes. Here, we describe the characterization of a MINPP from the Gram-positive bacterium Bifidobacterium longum (BlMINPP). BlMINPP has a typical HP2P-fold but, unusually, possesses a large alpha-domain polypeptide insertion relative to other MINPPs. This insertion, termed the U-loop, spans the active site and contributes to substrate specificity pockets underpopulated in other HP2Ps. Mutagenesis of U-loop residues reveals its contribution to enzyme kinetics and thermostability. Moreover, four crystal structures of the protein along the catalytic cycle capture, for the first time in an HP2P, a large ligand-driven alpha-domain motion essential to allow substrate access to the active site. This motion recruits residues both downstream of a molecular hinge and on the U-loop to participate in specificity subsites, and mutagenesis identified a mobile lysine residue as a key determinant of positional specificity of the enzyme. Taken together, these data provide important new insights to the factors determining stability, substrate recognition, and the structural mechanism of hydrolysis in this industrially important group of enzymes. Snapshots during the catalytic cycle of a histidine acid phytase reveal an induced-fit structural mechanism.,Acquistapace IM, Zi Etek MA, Li AWH, Salmon M, Kuhn I, Bedford MR, Brearley CA, Hemmings AM J Biol Chem. 2020 Dec 18;295(51):17724-17737. doi: 10.1074/jbc.RA120.015925. PMID:33454010 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Proteopedia Page Contributors and Editors (what is this?)

OCA