title: Functional analysis of propeptide as an intramolecular chaperone for in vivo folding of subtilisin nattokinase.
abstract: Here, we show that during in vivo folding of the precursor, the propeptide of subtilisin nattokinase functions as an intramolecular chaperone (IMC) that organises the in vivo folding of the subtilisin domain. Two residues belonging to β-strands formed by conserved regions of the IMC are crucial for the folding of the subtilisin domain through direct interactions. An identical protease can fold into different conformations in vivo due to the action of a mutated IMC, resulting in different kinetic parameters. Some interfacial changes involving conserved regions, even those induced by the subtilisin domain, blocked subtilisin folding and altered its conformation. Insight into the interaction between the subtilisin and IMC domains is provided by a three-dimensional structural model.
authors.affiliation: State Key Laboratory of Virology, Department of Biochemistry and Molecular Biology, College of Life Sciences, Wuhan University, Wuhan, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Jia
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Bao
authors.forename: Meizhi
authors.initials: M
authors.lastname: Weng
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Cai
authors.forename: Zhongliang
authors.initials: Z
authors.lastname: Zheng
authors.forename: Guolin
authors.initials: G
authors.lastname: Zou
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology; D017124:Conserved Sequence; D007700:Kinetics; D018832:Molecular Chaperones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D017510:Protein Folding; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D058849:Protein Refolding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013381:Subtilisins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D018832:Molecular Chaperones; D011498:Protein Precursors; D013381:Subtilisins; C053771:nattokinase