德国康斯坦茨大学J. S. Hartig团队发现了细菌中一种依赖于Ni2+的胍水解酶。相关论文于2022年3月9日在线发表在《自然》杂志上。
Author: Funck, D., Sinn, M., Fleming, J. R., Stanoppi, M., Dietrich, J., Lpez-Igual, R., Mayans, O., Hartig, J. S.
Issue&Volume: 2022-03-09
Abstract: Nitrogen availability is a growth-limiting factor in many habitats1, and the global nitrogen cycle involves prokaryotes and eukaryotes competing for this precious resource. Only some bacteria and archaea can fix elementary nitrogen; all other organisms depend on the assimilation of mineral or organic nitrogen. The nitrogen-rich compound guanidine occurs widely in nature2,3,4, but its utilization is impeded by pronounced resonance stabilization5, and enzymes catalysing hydrolysis of free guanidine have not been identified. Here we describe the arginase family protein GdmH (Sll1077) from Synechocystis sp. PCC 6803 as a Ni2+-dependent guanidine hydrolase. GdmH is highly specific for free guanidine. Its activity depends on two accessory proteins that load Ni2+ instead of the typical Mn2+ ions into the active site. Crystal structures of GdmH show coordination of the dinuclear metal cluster in a geometry typical for arginase family enzymes and allow modelling of the bound substrate. A unique amino-terminal extension and a tryptophan residue narrow the substrate-binding pocket and identify homologous proteins in further cyanobacteria, several other bacterial taxa and heterokont algae as probable guanidine hydrolases. This broad distribution suggests notable ecological relevance of guanidine hydrolysis in aquatic habitats.
DOI: 10.1038/s41586-022-04490-x
Source: https://www.nature.com/articles/s41586-022-04490-x
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
