3WGC

Aeromonas jandaei L-allo-threonine aldolase H128Y/S292R double mutant

Summary for 3WGC

• Entry DOI: 10.2210/pdb3wgc/pdb
• Related: 3WGB
• Descriptor: L-allo-threonine aldolase, N-GLYCINE-[3-HYDROXY-2-METHYL-5-PHOSPHONOOXYMETHYL-PYRIDIN-4-YL-METHANE] (3 entities in total)
• Functional Keywords: lyase, pyridoxal-5'-phosphate, threonine aldolase
• Biological source: Aeromonas jandaei
• Total number of polymer chains: 4
• Total formula weight: 148056.88

Authors

Qin, H.M.,Imai, F.L.,Miyakawa, T.,Kataoka, M.,Okai, M.,Ohtsuka, J.,Hou, F.,Nagata, K.,Shimizu, S.,Tanokura, M. (deposition date: 2013-08-03, release date: 2014-07-09, Last modification date: 2024-03-20)

Primary citation

Qin, H.M.,Imai, F.L.,Miyakawa, T.,Kataoka, M.,Kitamura, N.,Urano, N.,Mori, K.,Kawabata, H.,Okai, M.,Ohtsuka, J.,Hou, F.,Nagata, K.,Shimizu, S.,Tanokura, M.
L-allo-Threonine aldolase with an H128Y/S292R mutation from Aeromonas jandaei DK-39 reveals the structural basis of changes in substrate stereoselectivity.
Acta Crystallogr.,Sect.D, 70:1695-1703, 2014

PubMed Abstract: L-allo-Threonine aldolase (LATA), a pyridoxal-5'-phosphate-dependent enzyme from Aeromonas jandaei DK-39, stereospecifically catalyzes the reversible interconversion of L-allo-threonine to glycine and acetaldehyde. Here, the crystal structures of LATA and its mutant LATA_H128Y/S292R were determined at 2.59 and 2.50 Å resolution, respectively. Their structures implied that conformational changes in the loop consisting of residues Ala123-Pro131, where His128 moved 4.2 Å outwards from the active site on mutation to a tyrosine residue, regulate the substrate specificity for L-allo-threonine versus L-threonine. Saturation mutagenesis of His128 led to diverse stereoselectivity towards L-allo-threonine and L-threonine. Moreover, the H128Y mutant showed the highest activity towards the two substrates, with an 8.4-fold increase towards L-threonine and a 2.0-fold increase towards L-allo-threonine compared with the wild-type enzyme. The crystal structures of LATA and its mutant LATA_H128Y/S292R reported here will provide further insights into the regulation of the stereoselectivity of threonine aldolases targeted for the catalysis of L-allo-threonine/L-threonine synthesis.

PubMed: 24914980
DOI: 10.1107/S1399004714007664

Experimental method

X-RAY DIFFRACTION (2.5 Å)