7TVM

Viral AMG chitosanase V-Csn, apo structure, crystal form 2

Summary for 7TVM

• Entry DOI: 10.2210/pdb7tvm/pdb
• Descriptor: Viral chitosanase V-Csn, 1,2-ETHANEDIOL (3 entities in total)
• Functional Keywords: glycosyl hydrolase, chitosanase, viral auxiliary metabolic gene, dimer, hydrolase
• Biological source: unclassified sequences
• Total number of polymer chains: 2
• Total formula weight: 47990.74

Authors

Smith, C.A.,Wu, R.,Buchko, G.W.,Cort, J.R.,Hofmockel, K.S.,Jansson, J.K. (deposition date: 2022-02-05, release date: 2022-10-05, Last modification date: 2023-10-18)

Primary citation

Wu, R.,Smith, C.A.,Buchko, G.W.,Blaby, I.K.,Paez-Espino, D.,Kyrpides, N.C.,Yoshikuni, Y.,McDermott, J.E.,Hofmockel, K.S.,Cort, J.R.,Jansson, J.K.
Structural characterization of a soil viral auxiliary metabolic gene product - a functional chitosanase.
Nat Commun, 13:5485-5485, 2022

PubMed Abstract: Metagenomics is unearthing the previously hidden world of soil viruses. Many soil viral sequences in metagenomes contain putative auxiliary metabolic genes (AMGs) that are not associated with viral replication. Here, we establish that AMGs on soil viruses actually produce functional, active proteins. We focus on AMGs that potentially encode chitosanase enzymes that metabolize chitin - a common carbon polymer. We express and functionally screen several chitosanase genes identified from environmental metagenomes. One expressed protein showing endo-chitosanase activity (V-Csn) is crystalized and structurally characterized at ultra-high resolution, thus representing the structure of a soil viral AMG product. This structure provides details about the active site, and together with structure models determined using AlphaFold, facilitates understanding of substrate specificity and enzyme mechanism. Our findings support the hypothesis that soil viruses contribute auxiliary functions to their hosts.

PubMed: 36123347
DOI: 10.1038/s41467-022-32993-8

Experimental method

X-RAY DIFFRACTION (1.35 Å)