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Publication Abstract from PubMed

Poly(aspartic acid) (PAA) is a common water-soluble polycarboxylate used in a broad range of applications. PAA biodegradation and environmental assimilation were first identified in river water bacterial strains, Sphingomonas sp. KT-1 and Pedobacter sp. KP-2. Within Sphingomonas sp. KT-1, PahZ1KT-1 cleaves beta-amide linkages to oligo(aspartic acid) and then is degraded by PahZ2KT-1. Recently, we reported the first structure for PahZ1KT-1. Here, we report novel structures for PahZ2KT-1 bound to either Gd(3+)/Sm(3+) or Zn(2+) cations in a dimeric state consistent with M28 metallopeptidase family members. PahZ2KT-1 monomers include a dimerization domain and a catalytic domain with dual Zn(2+) cations. MD methods predict the putative substrate binding site to span across the dimerization and catalytic domains, where NaCl promotes the transition from an open conformation to a closed conformation that positions the substrate adjacent to catalytic zinc ions. Structural knowledge of PahZ1KT-1 and PahZ2KT-1 will allow for protein engineering endeavors to develop novel biodegradation reagents.

Sphingomonas sp. KT-1 PahZ2 Structure Reveals a Role for Conformational Dynamics in Peptide Bond Hydrolysis.,Brambley CA, Yared TJ, Gonzalez M, Jansch AL, Wallen JR, Weiland MH, Miller JM J Phys Chem B. 2021 Jun 10;125(22):5722-5739. doi: 10.1021/acs.jpcb.1c01216. Epub, 2021 Jun 1. PMID:34060838^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.