一种来自深海细菌的抗生素耐药酶
Marta Toth1, Clyde Smith, Hilary Frase
1Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
Journal of the American Chemical Society
|December 17, 2009
概括
研究人员发现了OIH-1,一种高度耐盐的β-乳酸酶酶,来自太平洋深海. 这种抗生素耐药性酶提供了对极端海洋环境中蛋白质演变的见解.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 海洋微生物学 海洋微生物学
背景情况:
- β-乳酸酶是赋予抗生素耐药性的酶.
- 深海是一个极端的环境,盐度很高.
- 了解来自这种环境的酶可以揭示新的进化适应.
研究的目的:
- 描述来自深海细菌Oceanobacillus iheyensis的一种新型A类β-乳糖酶OIH-1的结构和功能.
- 研究OIH-1中极端耐性的分子基础.
- 在孤立的海洋生态系统中探索抗生素耐药性酶的进化影响.
主要方法:
- 使用X射线晶体学以1.25 Å分辨率确定OIH-1的分子结构.
- 评估了酶动力学以评估不同度下基质水解.
- 进行了生物信息分析,将OIH-1与陆地β-lactamases进行比较.
主要成果:
- OIH-1是一种高度熟练的A类β-乳糖酶,在和NaCl度下运行最佳,表现出极端的分耐受性.
- 确定的结构是迄今为止型蛋白质的最高分辨率结构.
- OIH-1具有独特的表面,富含酸性残留物,使其与陆地同类区别开来,并有助于其耐受性.
结论:
- OIH-1代表了发现的耐度最高的细菌酶结构,适应了太平洋深海的高盐度条件.
- 这种酶为研究极端环境压力下的蛋白质进化提供了一个独特的模型,独立于临床抗生素选择.
- 这些发现表明,在深海微生物群落中,存在一种新型抗生素耐药性酶的潜在储存库.
相关概念视频
01:18Deep Sea Microbial Ecology
The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...
01:30Development of Antibiotic Resistance
Antibiotic resistance is a major public health concern that arises when bacteria evolve mechanisms to withstand the effects of antibiotic treatments. This resistance can be intrinsic, acquired through genetic mutations, or transferred between bacteria via horizontal gene transfer. The development of antibiotic resistance poses significant challenges in treating bacterial infections and necessitates ongoing research to develop new therapeutic strategies.Intrinsic resistance occurs when bacterial...
01:18Other Unique Bacteria
Magnetic bacteria exhibit a directed movement called magnetotaxis, driven by structures called magnetosomes. These magnetosomes consist of chains of magnetic particles made of either magnetite (Fe₃O₄) or greigite (Fe₃S₄) and are organized in a linear conformation by a protein scaffold within invaginations of the cell membrane. The bacteria align along the north–south magnetic field lines, much like a compass needle. They are typically microaerophilic or anaerobic and are commonly found near the...
01:25Mechanism of Antibiotic Resistance in MRSA
Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
00:57Antibiotic Selection
Overview
01:25Clinical Significance of Antibiotic Resistance
Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...