MamZ protein plays an essential role in magnetosome maturation process of Magnetospirillum gryphiswaldense MSR-1  

作　　者：Sha WU Qing WANG Xu WANG Ruixue GUO Tongwei ZHANG Yongxin PAN Feng LI Ying LI 

机构地区：[1]Engineering Technology Research Center of Ecological Restoration and Comprehensive Utilization of Coal Mining Collapse Area,Anhui Province,Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation,College of Life Sciences,Huaibei Normal University,Huaibei 235000,China [2]State Key Laboratories for Agro-biotechnology,China Agricultural University,Beijing 100193,China [3]Paleomagnetism and Geochronology Laboratory,Key Laboratory of Earth and Planetary Physics,Institute of Geology and Geophysics,Chinese Academy of Sciences,France-China Joint Laboratory for Evolution and Development of Magnetotactic Multicelluar Organisms,Beijing 100029,China

出　　处：《Journal of Oceanology and Limnology》2021年第6期2082-2096,共15页海洋湖沼学报（英文）

基　　金：Supported by the National Natural Science Foundation of China(No.31270093);the Innovation Team of Scientific Research Platform of Anhui Province(No.KJ2015TD001);the Open Project Program of the Collaborative Innovation Center for Modern Bio-manufacture,Anhui University(No.BM2015010)。

摘　　要：Based on analysis of gene structure of mamXY operon in Magnetospirillum gryphiswaldense strain MSR-1,we constructed a mamZ deletion mutant strain(ΔmamZ)and four complemented strains with different mamZ fragment lengths.Various cell phenotypic and physiological parameters were evaluated and compared among the wild-type(WT),mutant,and complemented strains.Cell growth rates were not notably different;however,magnetic response(Cmag)and iron uptake ability were significantly lower inΔmamZ.High-resolution transmission electron microscopy(HR-TEM)showed that magnetosomes inΔmamZ were small and irregular,and rock magnetic measurements suggested that they contained immature particles.In comparison to WT of MSR-1,intracellular iron content ofΔmamZ and the complemented strains cultured with 20mmol/L iron source was similar or slightly higher.The complemented strains were unable to synthesize mature or normal amounts of magnetosomes,apparently because of abnormal expression of the transmembrane domain of MamZ protein.Real-time reverse transcription polymerase chain reaction(RTqPCR)analysis showed that relative transcription levels of mamX and ftsZ-like genes inΔmamZ were higher at 18 h than at 12 h,suggesting that MamXY proteins play cooperative functional roles in the magnetosome maturation process.Transcription level of mms6 was significantly upregulated inΔmamZ(incubated at 12 h)and the complemented strains(incubated at 12 and 18 h),refl ecting possible interaction between MamXY and Mms6 proteins during magnetosome biosynthesis.These findings,taken together,demonstrate the essential role of MamZ in the magnetosome maturation process in MSR-1.

关 键 词：Magnetospirillum gryphiswaldense mamZ deletion mamXY operon magnetosome maturation 

分 类 号：Q64[生物学—生物物理学]