中文摘要：人类肺炎支原体MPN387蛋白在支原体滑移方面起着重要作用，为阐明人类肺炎支原体的滑移机制，本研究分析了MPN387蛋白的结构。该蛋白由358个氨基酸组成，在72-290位氨基酸之间包含一个卷曲螺旋结构。MPN387蛋白为一个哑铃形的同型二聚体，长度为42.7 nm、直径为9.1 nm，包含一个24.5 nm长的中枢平行卷曲螺旋部分。
外文摘要：Mycoplasma pneumoniae is a human pathogen that glides on host cell surfaces with repeated catch and release of sialylated oligosaccharides. At a pole, this organism forms a protrusion called the attachment organelle, which is composed of surface structures, including P1 adhesin and the internal core structure. The core structure can be divided into three parts, the terminal button, paired plates, and bowl complex, aligned in that order from the front end of the protrusion. To elucidate the gliding mechanism, we focused on MPN387, a component protein of the bowl complex which is essential for gliding but dispensable for cytadherence. The predicted amino acid sequence showed that the protein features a coiled-coil region spanning residue 72 to residue 290 of the total of 358 amino acids in the protein. Recombinant MPN387 proteins were isolated with and without an enhanced yellow fluorescent protein (EYFP) fusion tag and analyzed by gel filtration chromatography, circular dichroism spectros-copy, analytical ultracentrifugation, partial proteolysis, and rotary-shadowing electron microscopy. The results showed that MPN387 is a dumbbell-shaped homodimer that is about 42.7 nm in length and 9.1 nm in diameter and includes a 24.5-nm-long central parallel coiled-coil part. The molecular image was superimposed onto the electron micrograph based on the localizing position mapped by fluorescent protein tagging. A proposed role of this protein in the gliding mechanism is discussed. IMPORTANCE Human mycoplasma pneumonia is caused by a pathogenic bacterium, Mycoplasma pneumoniae. This tiny, 2-mu m-long bacterium is suggested to infect humans by gliding on the surface of the trachea through binding to sialylated oligosaccharides. The mechanism underlying mycoplasma "gliding motility" is not related to any other well-studied motility systems, such as bacterial flagella and eukaryotic motor proteins. Here, we isolated and analyzed the structure of a key protein which is directly involved in the gliding mechanism.
外文关键词：ELECTRON-MICROSCOPY；ANALYTICAL ULTRACENTRIFUGATION；IN-VITRO； CYTADHERENCE； MOBILE；MODEL； MECHANISM； CENTIPEDE；ORGANELLE； BINDING
作者：Kawakita, Y；Kinoshita, M；Furukawa, Y等
作者单位：日本大阪城市大学
期刊名称：JOURNAL OF BACTERIOLOGY
期刊影响因子：3.198
出版年份：2016
出版刊次：9
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