Glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) is an evolutionarily conserved essential enzyme in the glycolytic pathway. GAPDH is also involved in a wide spectrum of non‐catalytic cellular ‘moonlighting’ functions. Bacterial surface‐associated GAPDHs engage in many host interactions that aid in colonization, pathogenesis, and virulence. We have structurally and functionally characterized the recombinant GAPDH of the obligate intracellular bacteria Chlamydia trachomatis, the leading cause of sexually transmitted bacterial and ocular infections. Contrary to earlier speculations, recent data confirm the presence of glucose‐catabolizing enzymes including GAPDH in both stages of the biphasic life cycle of the bacterium. The high‐resolution crystal structure described here provides a close‐up view of the enzyme's active site and surface topology and reveals two chemically modified cysteine residues. Moreover, we show for the first time that purified C. trachomatis GAPDH binds to human plasminogen and plasmin. Based on the versatility of GAPDH's functions, data presented here emphasize the need for investigating the Chlamydiae GAPDH's involvement in biological functions beyond energy metabolism.

中文翻译：

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沙眼衣原体甘油醛 3-磷酸脱氢酶：酶动力学、高分辨率晶体结构和纤溶酶原结合

3-磷酸​​甘油醛脱氢酶（GAPDH）是糖酵解途径中进化上保守的必需酶。GAPDH 还涉及广泛的非催化细胞“月光”功能。细菌表面相关的 GAPDH 参与许多宿主相互作用，有助于定植、发病机制和毒力。我们已经在结构和功能上表征了专性细胞内细菌沙眼衣原体的重组 GAPDH，性传播细菌和眼部感染的主要原因。与早期的推测相反，最近的数据证实了在细菌双相生命周期的两个阶段都存在葡萄糖分解酶，包括 GAPDH。这里描述的高分辨率晶体结构提供了酶活性位点和表面拓扑结构的特写视图，并揭示了两个化学修饰的半胱氨酸残基。此外，我们首次展示了纯化的C。沙眼GAPDH 与人纤溶酶原和纤溶酶结合。基于 GAPDH 功能的多功能性，这里提供的数据强调需要调查衣原体GAPDH 在能量代谢之外的生物功能中的参与。