Asparaginase: Difference between revisions

The first L-asparaginase structure was published and deposited in the PDB in 1993 for the EcAII enzyme <ref>PMID:8434007</ref> and may serve as an example of a <scene name='52/525144/3eca_cartoon/8'>Class 1 type II enzyme EcAII</scene>. Structure of <scene name='52/525144/Ecai_2p2n/3'>Class 1 type I enzymes is exemplified by EcAI</scene><ref>PMID:17451745</ref>, whereas<scene name='52/525144/Ecaiii_2zal/3'>Class 2 type III enzymes may be represented by EcAIII</scene><ref>PMID:15159592</ref><ref>PMID:18334484</ref>. Class 2 L-asparaginases belong to the family of Ntn-hydrolases, which are expressed as inactive precursors that must undergo autoproteolytic cleavage into α and β subunits to achieve maturation<ref>PMID:35626629</ref>. While the existence of an alien type of ASNase in the symbiotic nitrogen-fixing bacterium ''Rhizobium etli'' had been recognized long ago<ref>PMID:11996000</ref>, the structure of the <scene name='52/525144/Reav_7os5/2'>iducible and thermolabile prototype Class 3 ReAV</scene> was solved and deposited in the PDB only recently<ref>PMID:34795296</ref>, followed by structures of the constitutive and thermostable isoform ReAIV<ref>PMID:37494066</ref>. More than 200 structures of ASNases have been deposited in the Protein Data Bank (PDB) by April 2024<ref>PMID:34060231</ref><ref name="Wlodawer">Wlodawer, A., Dauter, Z., Lubkowski, J.,  Loch, J.I., Brzezinski, D., Gilski, M., Jaskolsk, M. (2024) Toward a dependable dataset of structures for L-asparaginase research(submitted).</ref>.