ジャーナル: Nat Commun / 年: 2024 タイトル: Mechanistic insights into lanthipeptide modification by a distinct subclass of LanKC enzyme that forms dimers. 著者: Yifan Li / Kai Shao / Zhaoxing Li / Kongfu Zhu / Bee Koon Gan / Jian Shi / Yibei Xiao / Min Luo / 要旨: Naturally occurring lanthipeptides, peptides post-translationally modified by various enzymes, hold significant promise as antibiotics. Despite extensive biochemical and structural studies, the ...Naturally occurring lanthipeptides, peptides post-translationally modified by various enzymes, hold significant promise as antibiotics. Despite extensive biochemical and structural studies, the events preceding peptide modification remain poorly understood. Here, we identify a distinct subclass of lanthionine synthetase KC (LanKC) enzymes with distinct structural and functional characteristics. We show that PneKC, a member of this subclass, forms a dimer and possesses GTPase activity. Through three cryo-EM structures of PneKC, we illustrate different stages of peptide PneA binding, from initial recognition to full binding. Our structures show the kinase domain complexed with the PneA core peptide and GTPγS, a phosphate-bound lyase domain, and an unconventional cyclase domain. The leader peptide of PneA interact with a gate loop, transitioning from an extended to a helical conformation. We identify a dimerization hot spot and propose a "negative cooperativity" mechanism toggling the enzyme between tense and relaxed conformation. Additionally, we identify an important salt bridge in the cyclase domain, differing from those in in conventional cyclase domains. These residues are highly conserved in the LanKC subclass and are part of two signature motifs. These results unveil potential differences in lanthipeptide modification enzymes assembly and deepen our understanding of allostery in these multifunctional enzymes.
全体 : Dimeric structure of Class III lanthipeptide modification enzyme ...
全体
名称: Dimeric structure of Class III lanthipeptide modification enzyme PneKC with one protomer in complex with substrate PneA and GTP
要素
複合体: Dimeric structure of Class III lanthipeptide modification enzyme PneKC with one protomer in complex with substrate PneA and GTP
タンパク質・ペプチド: Protein kinase domain-containing protein
タンパク質・ペプチド: PneA LP
リガンド: GUANOSINE-5'-TRIPHOSPHATE
リガンド: PHOSPHATE ION
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超分子 #1: Dimeric structure of Class III lanthipeptide modification enzyme ...
超分子
名称: Dimeric structure of Class III lanthipeptide modification enzyme PneKC with one protomer in complex with substrate PneA and GTP タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: #1-#2
由来(天然)
生物種: Streptococcus pneumoniae (肺炎レンサ球菌)
分子量
理論値: 210 KDa
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分子 #1: Protein kinase domain-containing protein
分子
名称: Protein kinase domain-containing protein / タイプ: protein_or_peptide / ID: 1 / コピー数: 2 / 光学異性体: LEVO