Ramón Roth Isabel, Kats Pavel, Fiebig Timm, Routier Françoise, Fedorov Roman, Dirr Larissa, Führing Jana I
Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany.
mBio. 2025 Feb 5;16(2):e0207124. doi: 10.1128/mbio.02071-24. Epub 2024 Dec 20.
In all kingdoms of life, the enzyme uridine diphosphate-glucose pyrophosphorylase (UGP) occupies a central role in metabolism, as its reaction product uridine diphosphate-glucose (UDP-Glc) is involved in various crucial cellular processes. Pathogens, including fungi, parasites, and bacteria, depend on UGP for the synthesis of virulence factors; in particular, various bacterial species utilize UDP-Glc and its derivatives for the synthesis of lipopolysaccharides, capsular polysaccharides, and biofilm exopolysaccharides. UGPs have, therefore, gained attention as anti-bacterial drug target candidates, prompting us to study their structure-function relationships to provide a basis for the rational development of specific inhibitors. UGP function is tied to its oligomeric state, and the majority of bacterial homologs have been described as tetramers encoded by the gene. Uniquely, enterobacterial species harbor a second gene, , encoding a protein with high homology to UGP, whose function is somewhat controversial. Here, we show that the gene of the opportunistic pathogen encodes a dimeric protein that has lost UGP activity, likely due to a combination of active site mutations and an inability to tetramerize, whereas the functional UGP, encoded by , is an active tetramer. Our AlphaFold-assisted structure-function relationship studies underline that tetramerization is essential for bacterial UGP function and is facilitated by a common mechanism utilizing conserved key residues. Targeting the respective molecular interfaces, which are absent in human UGP, could provide a means of selectively inhibiting the bacterial virulence factor UGP and potentially rendering pathogenic species avirulent.IMPORTANCEThe enzyme uridine diphosphate-glucose pyrophosphorylase (UGP) is important for the virulence of bacterial pathogens and, therefore, a potential drug target. In this study, we identify the gene encoding the functional UGP in , a bacterium notoriously causing severe antibiotic-resistant infections in humans, and reveal structural and functional features that may aid in the development of new antibiotics.
在所有生物界中，尿苷二磷酸葡萄糖焦磷酸化酶（UGP）在新陈代谢中占据核心地位，因为其反应产物尿苷二磷酸葡萄糖（UDP - Glc）参与了各种关键的细胞过程。包括真菌、寄生虫和细菌在内的病原体，其毒力因子的合成依赖于UGP；特别是，多种细菌利用UDP - Glc及其衍生物来合成脂多糖、荚膜多糖和生物膜胞外多糖。因此，UGP作为抗菌药物靶点候选物受到了关注，这促使我们研究它们的结构 - 功能关系，为合理开发特异性抑制剂提供依据。UGP的功能与其寡聚状态相关，大多数细菌同源物被描述为由基因编码的四聚体。独特的是，肠道细菌物种含有第二个基因，该基因编码一种与UGP具有高度同源性的蛋白质，其功能存在一定争议。在这里，我们表明机会致病菌的基因编码一种二聚体蛋白，该蛋白已丧失UGP活性，可能是由于活性位点突变和无法形成四聚体的共同作用，而由编码的功能性UGP是一种活性四聚体。我们基于AlphaFold的结构 - 功能关系研究强调，四聚化对于细菌UGP功能至关重要，并且通过利用保守关键残基的共同机制得以促进。靶向人类UGP中不存在的各自分子界面，可能提供一种选择性抑制细菌毒力因子UGP并潜在使致病物种无毒的方法。重要性尿苷二磷酸葡萄糖焦磷酸化酶（UGP）对细菌病原体的毒力很重要，因此是一个潜在的药物靶点。在这项研究中，我们鉴定了在一种臭名昭著的导致人类严重耐药感染的细菌中编码功能性UGP的基因，并揭示了可能有助于开发新抗生素的结构和功能特征。
