7OS3

Crystal structure of Rhizobium etli inducible L-asparaginase ReAV solved by S-SAD (orthorhombic form START)

This is a non-PDB format compatible entry.

Summary for 7OS3

• Entry DOI: 10.2210/pdb7os3/pdb
• Descriptor: L-asparaginase II protein, ZINC ION, CHLORIDE ION, ... (4 entities in total)
• Functional Keywords: l-asparaginase, amidohydrolase, rhizobium etli, s-sad, hydrolase
• Biological source: Rhizobium etli (strain CFN 42 / ATCC 51251)
• Total number of polymer chains: 2
• Total formula weight: 79311.46

Authors

Gilski, M.,Loch, J.I.,Imiolczyk, B.,Jaskolski, M. (deposition date: 2021-06-07, release date: 2021-11-24, Last modification date: 2024-06-19)

Primary citation

Loch, J.I.,Imiolczyk, B.,Sliwiak, J.,Wantuch, A.,Bejger, M.,Gilski, M.,Jaskolski, M.
Crystal structures of the elusive Rhizobium etli L-asparaginase reveal a peculiar active site.
Nat Commun, 12:6717-6717, 2021

PubMed Abstract: Rhizobium etli, a nitrogen-fixing bacterial symbiont of legume plants, encodes an essential L-asparaginase (ReAV) with no sequence homology to known enzymes with this activity. High-resolution crystal structures of ReAV show indeed a structurally distinct, dimeric enzyme, with some resemblance to glutaminases and β-lactamases. However, ReAV has no glutaminase or lactamase activity, and at pH 9 its allosteric asparaginase activity is relatively high, with K for L-Asn at 4.2 mM and k of 438 s. The active site of ReAV, deduced from structural comparisons and confirmed by mutagenesis experiments, contains a highly specific Zn binding site without a catalytic role. The extensive active site includes residues with unusual chemical properties. There are two Ser-Lys tandems, all connected through a network of H-bonds to the Zn center, and three tightly bound water molecules near Ser48, which clearly indicate the catalytic nucleophile.

PubMed: 34795296
DOI: 10.1038/s41467-021-27105-x

Experimental method

X-RAY DIFFRACTION (2.177 Å)