Product Specificity of C4-Reductases in the Biosynthesis of GDP-6-Deoxy-Heptoses during Capsular Polysaccharide Formation in Campylobacter jejuni.
Product Specificity of C4-Reductases in the Biosynthesis of GDP-6-Deoxy-Heptoses during Capsular Polysaccharide Formation in Campylobacter jejuni.
复制标题
空肠弯曲杆菌荚膜多糖形成过程中 C4 还原酶在 GDP-6-脱氧庚糖生物合成中的产物特异性。
DOI：
10.1021/acs.biochem.2c00365
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发表时间：
2022-10-04
期刊：
影响因子：
2.9
通讯作者：
Raushel, Frank M.
中科院分区：
文献类型：
--
作者：
Ghosh, Manas K.;Xiang, Dao Feng;Raushel, Frank M.
在美国和欧洲，空肠弯曲杆菌是导致食物中毒的主要原因。包裹在细菌外部的荚膜多糖有助于逃避宿主的免疫系统。已鉴定出至少33种不同的空肠梭菌菌株，并从不同的血清型中鉴定了12种不同的荚膜多糖的化学结构。到目前为止，在具有化学特征的荚膜多糖中已经发现了10种不同的庚糖，目前认为每种庚糖都是通过4,6-脱氢酶（或c4 -脱氢酶）、C3-或C3/ c5 -外聚酶和c4 -还原酶的连续作用对gdp -d-甘油-d-甘露-庚糖进行修饰而产生的。在已测序的空肠梭菌菌株中，我们鉴定出25种不同的c4 -还原酶，它们聚集在9个群中，序列同源性为> - 90%。从7个不同的簇中纯化了8个蛋白质，并使用NMR和esi -质谱法用gdp -6-脱氧-4-酮-庚糖底物测定了它们的产物谱。分离产物包括gdp -6-脱氧- 1 -葡萄糖-庚糖（血清型HS:2）、gdp -6-脱氧- 1 -半乳糖-庚糖（血清型HS:42）、gdp -6-脱氧- 1 -谷-庚糖（血清型HS:15）、gdp -6-脱氧-d-胰-庚糖（血清型HS:3、HS:4和HS:33）、gdp -6-脱氧-d-甘露-庚糖（血清型HS:53）和gdp -6-脱氧-d-乙酰-庚糖（血清型HS:23/36）。基于这些观察结果，可以可靠地预测来自空肠梭菌的另外14种c4还原酶的产物特异性。其余三种c4还原酶很可能是3,6-二脱氧-庚糖产物的生物合成所必需的。
Campylobacter jejuni is the leading cause of food poisoning in the United States and Europe. A capsular polysaccharide that coats the exterior of the bacterium helps evade the host immune system. At least 33 different strains of C. jejuni have been identified and the chemical structures of 12 different capsular polysaccharides have been characterized from various serotypes. Thus far, 10 different heptose sugars have been found in the chemically characterized capsular polysaccharides and each of these are currently thought to originate from the modification of GDP-d-glycero-d-manno-heptose by the successive action of a 4,6-dehydratase (or C4-dehydrogenase), C3- or C3/C5-epimerase, and C4-reductase. Within the sequenced strains of C. jejuni, we have identified 25 different C4-reductases that cluster into 9 groups at a sequence identity of >90%. Eight of the proteins from seven different clusters were purified and their product profiles determined with GDP-6-deoxy-4-keto-heptose substrates using NMR and ESI-mass spectrometry. The isolated products included GDP-6-deoxy-l-gluco-heptose (serotype HS:2), GDP-6-deoxy-l-galacto-heptose (serotype HS:42), GDP-6-deoxy-l-gulo-heptose (serotype HS:15), GDP-6-deoxy-d-ido-heptose (serotypes HS:3, HS:4, and HS:33), GDP-6-deoxy-d-manno-heptose (serotype HS:53) and GDP-6-deoxy-d-altro-heptose (serotype HS:23/36). Based on these observations the product specificity can be reliably predicted for 14 additional C4-reductases from C. jejuni. The remaining three C4-reductases are highly likely to be required for the biosynthesis of 3,6-dideoxy-heptose products.
影响因子：
14.9
作者：
Bayliss CD;Bidmos FA;Anjum A;Manchev VT;Richards RL;Grossier JP;Wooldridge KG;Ketley JM;Barrow PA;Jones MA;Tretyakov MV
通讯作者：
Tretyakov MV