title: Alanine 32 in PilA is important for PilA stability and type IV pili function in Myxococcus xanthus.
abstract: Type IV pili (TFP) are membrane-anchored filaments with a number of important biological functions. In the model organism Myxococcus xanthus, TFP act as molecular engines that power social (S) motility through cycles of extension and retraction. TFP filaments consist of several thousand copies of a protein called PilA or pilin. PilA contains an N-terminal α-helix essential for TFP assembly and a C-terminal globular domain important for its activity. The role of the PilA sequence and its structure-function relationship in TFP-dependent S motility remain active areas of research. In this study, we identified an M. xanthus PilA mutant carrying an alanine to valine substitution at position 32 in the α-helix, which produced structurally intact but retraction-defective TFP. Characterization of this mutant and additional single-residue variants at this position in PilA demonstrated the critical role of alanine 32 in PilA stability, TFP assembly and retraction.
authors.affiliation: Molecular Biology Institute, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan 250100, Shandong, PR China.|School of Dentistry, University of California, Los Angeles, CA 90095, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA 90095-7364, USA.|California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan 250100, Shandong, PR China.|School of Dentistry, University of California, Los Angeles, CA 90095, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Dentistry, University of California, Los Angeles, CA 90095, USA.
authors.forename: Renate
authors.initials: R
authors.lastname: Lux
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA 90095-7364, USA.|California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA.
authors.forename: Z Hong
authors.initials: ZH
authors.lastname: Zhou
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA 90095-7364, USA.|School of Dentistry, University of California, Los Angeles, CA 90095, USA.|Molecular Biology Institute, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.
authors.forename: Wenyuan
authors.initials: W
authors.lastname: Shi
mesh_terms: D000409:Alanine / Q000737:chemistry*; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D036781:Fimbriae Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D005838:Genotype; D020409:Molecular Motor Proteins / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D009154:Mutation; D016941:Myxococcus xanthus / Q000235:genetics* / Q000502:physiology*; D055550:Protein Stability; D013329:Structure-Activity Relationship
chemical_list: D001426:Bacterial Proteins; D020409:Molecular Motor Proteins; D036781:Fimbriae Proteins; D000409:Alanine