Turnover Chemistry and Structural Characterization of the Cj0843c Lytic Transglycosylase of Campylobacter jejuni.
Turnover Chemistry and Structural Characterization of the Cj0843c Lytic Transglycosylase of Campylobacter jejuni.
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DOI：
10.1021/acs.biochem.1c00027
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发表时间：
2021-04-13
期刊：
影响因子：
2.9
通讯作者：
van den Akker, Focco
中科院分区：
文献类型：
--
作者：
Kumar, Vijay;Mathure, Snigdha A.;Lee, Mijoon;Boorman, Jacob;Zeng, Ximin;Lin, Jun;Hesek, Dusan;Lastochkin, Elena;Mobashery, Shahriar;van den Akker, Focco
来自空肠弯曲菌的可溶性溶解性转糖基酶Cj 0843 c分解细胞壁肽聚糖（PG）。其非水解活性维持细胞壁重塑和修复。我们在此报告我们的结构-功能研究探测底物的偏好和识别这种酶。我们的研究表明，Cj 0843 c表现出外溶和内溶活性，并形成N-乙酰基-1，6-脱水胞壁酰（anhMurNAc）肽聚糖末端，这是典型的裂解转糖基酶催化的转化。Cj 0843 c显示出偏好具有anhMurNAc末端的底物和具有肽茎的底物的趋势。突变显示催化E390对活性至关重要。此外，突变显示位于E390附近的带正电荷的口袋中的R388和K505也起重要作用。在这个带正电荷的口袋的另一侧，R326的突变增强了活性。我们的数据点带正电的残基在这个口袋中的生产性结合的主要是带负电荷的PG不同的角色。我们还表明，通过X-射线晶体学和MD模拟的Cj 0843 c的活性位点仍然能够结合GlcNAc含有二-和三聚体没有MurNAc部分，没有肽茎，没有anhMurNAc结束。
The soluble lytic transglycosylase Cj0843c from Campylobacter jejuni breaks down cell-wall peptidoglycan (PG). Its non-hydrolytic activity sustains cell-wall remodeling and repair. We report herein our structure-function studies probing the substrate preferences and recognition by this enzyme. Our studies show that Cj0843c exhibits both exolytic and endolytic activities and forms the N-acetyl-1,6-anhydromuramyl (anhMurNAc) peptidoglycan termini, the typical transformation catalyzed by lytic transglycosylase. Cj0843c shows a trend toward a preference of substrates with anhMurNAc ends and those with peptide stems. Mutagenesis revealed that the catalytic E390 is critical for activity. In addition, mutagenesis showed that R388 and K505, located in the positively charged pocket near E390, also serve important roles. Mutation of R326, on the opposite side of this positively charged pocket, enhanced activity. Our data point to different roles for positively charged residues in this pocket for productive binding of the predominantly negatively charged PG. We also show by X-ray crystallography and by MD simulations that the active site of Cj0843c is still capable of binding GlcNAc containing di- and trisaccharides without MurNAc moieties, without peptide stems, and without the anhMurNAc ends.
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影响因子：
4.6
作者：
Byun B;Mahasenan KV;Dik DA;Marous DR;Speri E;Kumarasiri M;Fisher JF;Hermoso JA;Mobashery S
通讯作者：
Mobashery S
影响因子：
3.6
作者：
Schaub, Ryan E.;Chan, Yolande A.;Dillard, Joseph P.
通讯作者：
Dillard, Joseph P.
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
3.2
作者：
Lee, Mijoon;Hesek, Dusan;Mobashery, Shahriar
通讯作者：
Mobashery, Shahriar
影响因子：
64.8
作者：
THUNNISSEN, AMWH;DIJKSTRA, AJ;DIJKSTRA, BW
通讯作者：
DIJKSTRA, BW