Caing-Carlsson Rhawnie, Goyal Parveen, Sharma Amit, Ghosh Swagatha, Setty Thanuja Gangi, North Rachel A, Friemann Rosmarie, Ramaswamy S
Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden.
Institute for Stem Cell Biology and Regenerative Medicine, GKVK Post, Bangalore 560 065, India.
Acta Crystallogr F Struct Biol Commun. 2017 Jun 1;73(Pt 6):356-362. doi: 10.1107/S2053230X17007439. Epub 2017 May 31.
Sialic acids comprise a varied group of nine-carbon amino sugars that are widely distributed among mammals and higher metazoans. Some human commensals and bacterial pathogens can scavenge sialic acids from their environment and degrade them for use as a carbon and nitrogen source. The enzyme N-acetylmannosamine kinase (NanK; EC 2.7.1.60) belongs to the transcriptional repressors, uncharacterized open reading frames and sugar kinases (ROK) superfamily. NanK catalyzes the second step of the sialic acid catabolic pathway, transferring a phosphate group from adenosine 5'-triphosphate to the C6 position of N-acetylmannosamine to generate N-acetylmannosamine 6-phosphate. The structure of NanK from Fusobacterium nucleatum was determined to 2.23 Å resolution by X-ray crystallography. Unlike other NanK enzymes and ROK family members, F. nucleatum NanK does not have a conserved zinc-binding site. In spite of the absence of the zinc-binding site, all of the major structural features of enzymatic activity are conserved.
唾液酸是一类由九个碳原子组成的氨基糖，种类多样，广泛分布于哺乳动物和高等后生动物中。一些人体共生菌和细菌病原体能够从周围环境中获取唾液酸并将其降解，用作碳源和氮源。N-乙酰甘露糖胺激酶（NanK；EC 2.7.1.60）属于转录抑制因子、未表征开放阅读框和糖激酶（ROK）超家族。NanK催化唾液酸分解代谢途径的第二步，将腺苷5'-三磷酸中的磷酸基团转移至N-乙酰甘露糖胺的C6位，生成N-乙酰甘露糖胺6-磷酸。通过X射线晶体学确定了具核梭杆菌NanK的结构，分辨率为2.23 Å。与其他NanK酶和ROK家族成员不同，具核梭杆菌NanK没有保守的锌结合位点。尽管没有锌结合位点，但酶活性的所有主要结构特征均得以保留。
