从乳球菌乳糖LAC46060中分析细菌素类lysin LysL中的细胞壁结合域
Samira Mokhtari1, Yanru Li2, Per E J Saris2
1Department of Microbiology, University of Helsinki, P.O. Box 56, 00014, Helsinki, Finland. samira.mokhtari@helsinki.fi.
Archives of microbiology
|July 2, 2024
概括
来自Lactococcus lactis的类似细菌素的lysin LysL的C末端含有特定的细胞壁结合域 (CBD). 这种CBD调解了目标特异性,解释了为什么LysL会影响敏感菌株,但不会影响耐药菌株或生产者.
科学领域:
- 微生物学 微生物学
- 分子生物学分子生物学
- 菌体研究 研究 菌体研究
背景情况:
- 野生类型的Lactococcus lactis菌株LAC460产生LysL,一种类似细菌素的溶酶,具有两个N端酶活性域 (EAD).
- 莱斯L的C端是不具特征的,并且缺乏与已知域的同质性,这促使人们对其在目标特异性中的作用进行了调查.
研究的目的:
- 为了确定LysL的C端是否具有细胞壁结合域 (CBD),负责其标特异性.
- 为了研究LysL C-terminus与各种乳球菌株的结合特性.
主要方法:
- 构建了一个编码LysL C终端假定CBD和His标记绿色光蛋白 (HGFPuv) 的基因融合.
- HGFPuv_CBDlysL融合蛋白在大肠杆菌中得到表达,并使用亲和染色法进行净化.
- 结合试验是通过将纯化的融合蛋白与LysL敏感和LysL耐药的乳球球菌株进行化,然后进行光显微镜和盘子阅读器分析来进行.
主要成果:
- HGFPuv_CBDlysL融合蛋白特别结合于LysL敏感的乳球球菌MG1614的细胞表面,由绿色光表示.
- 包括生产者Lactococcus lactis LAC460在内的LysL耐药菌株没有表现出光,不显示融合蛋白的结合.
- 光板阅读器分析证实了对四种经过测试的敏感菌株的特定结合,但对11种经过测试的耐药菌株没有.
结论:
- 实验证据证实,乳球菌菌素lysin LysL的C末端存在一种特定的细胞壁结合域 (CBD).
- LysL C-终端对敏感菌株的特定结合及其对包括生产者在内的耐药菌株的缺乏结合,为LysL的目标特异性和生产者的耐药性机制提供了洞察力.
相关概念视频
Bacterial Cell Wall
The bacterial cell wall is an essential structural component that encases the plasma membrane, preserving cellular integrity, determining shape, and protecting against osmotic stress. This rigid yet flexible structure primarily comprises peptidoglycan, a polymer that forms a mesh-like matrix conferring mechanical strength and flexibility.Peptidoglycan Composition and StructurePeptidoglycan, the core of the bacterial cell wall, comprises alternating units of N-acetylglucosamine (NAG) and...
Outer Layers of the Cell Envelope
The outermost layers of prokaryotic cells play a critical role in their survival, virulence, and interaction with the environment. These layers, often composed of polysaccharides, polypeptides, or proteins, form protective and adhesive structures that vary in organization and function.Capsules and Slime LayersCapsules are highly organized, tightly bound layers that firmly attach to the bacterial cell wall. Capsules are usually made of polysaccharides, though some are made of polypeptides. These...
Formation of Lipopolysaccharides
Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin, triggering...
Inducible Operons: lac Operon
The lac operon in Escherichia coli is a model for understanding inducible gene regulation and metabolic flexibility. It integrates local control by lactose and global regulation through catabolite repression, enabling E. coli to preferentially metabolize glucose when available and switch to lactose utilization when glucose is scarce.Structure and Function of the lac OperonThe lac operon contains three structural genes: lacZ (β-galactosidase), lacY (lactose permease), and lacA (thiogalactoside...
Archaeal Cell Wall
Archaeal cell walls are structurally and compositionally distinct from their bacterial counterparts, lacking the characteristic peptidoglycan layer found in most bacteria. Instead, archaeal cell walls exhibit remarkable diversity, utilizing materials such as pseudomurein, polysaccharides, and proteins to construct their protective outer layers. This structural flexibility is closely tied to archaea's ecological adaptability.S-Layers: The Common Archaeal Cell WallThe S-layer is the most...
Inhibitors of Gram-positive Cell Wall Synthesis
Bacterial cell walls are typically rigid structures composed mainly of peptidoglycan, a mesh-like polymer that provides mechanical strength and maintains cell shape. The synthesis of peptidoglycan is a crucial process in bacterial growth and serves as a primary target for many antibiotics.Mechanism of Action of Beta-Lactam AntibioticsBeta-lactam antibiotics, such as penicillin, inhibit peptidoglycan synthesis in actively growing cells. These antibiotics share a characteristic four-membered...


