来自口腔病原体Fusobacterium nucleatum的辅因子独立的histidine种族酶的发现,表征和结构
Tess Lamer1, Pu Chen2, Marie J Venter1
1Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada.
The Journal of biological chemistry
|October 18, 2024
概括
菌核酸菌具有一种独特的酶,histidine racemase (HisR),它可以有效地种族化L-histidine,而不是氨酸. 这一发现影响了对这种机会性病原体的理解.
科学领域:
- 微生物学和生物化学
- 细菌病原体的产生
- 酶学 是一种酶学.
背景情况:
- Fusobacterium nucleatum是一种口腔细菌,与牙周炎和其他疾病有关.
- F.核合成兰因的peptidoglycan,不同于大多数使用meso-2,6-diaminopimelic酸 (DAP) 的阴性细菌.
- 在F. nucleatum中预测的一种酶被假设为DAP表皮酶或氨酸表皮酶,但与氨酸的活性较低.
研究的目的:
- 描述Fusobacterium nucleatum中预测的表皮酶酶的功能.
- 为了确定酶的基质特异性和动力特性.
- 为了研究这种酶在F. nucleatum生长中的作用.
主要方法:
- 通过动力学实验对酶进行表征.
- 局部定向突变发生 (C67S,C209S) 以产生催化突变物.
- 进行X射线晶体学以确定酶结构.
- 在F. nucleatum中进行基因淘汰 (hisR),以评估生长表型.
主要成果:
- 这种酶被确定为一种histidine赛马酶 (HisR),L-histidine的周转率比L,L-lanthionine高约10,000倍.
- 他的R功能作为一个辅因子独立的种族酶,对histidine具有高特异性.
- 晶体结构揭示了催化氨酸突变的开放,基质未结合的构造.
- 在指数阶段,hisR淘汰导致F. nucleatum在指数阶段的生长中出现可重现的滞后.
结论:
- 这种特征的酶是一种histidine racemase (HisR),与以前研究的histidine racemase (如金黄色葡萄球菌CntK.不同.
- HisR的主要作用可能是histidine的种族化,而不是lanthionine的表皮化.
- 似乎HisR在F. nucleatum的生长中发挥了作用,F. nucleatum是一个重要的牙周病原体.
关键词:
这就是CntK.D-histidine 的使用方法这种细菌名为Fusobacterium nucleatum.黄金葡萄球菌黄金葡萄球菌它是独立于辅助因子的.兰氨酸是什么 兰氨酸是什么这是一场赛车狂欢,赛车狂欢.斯塔菲洛皮因 (Staphylopine) 是一种葡萄素.立体化学是一种立体化学.更多相关视频
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