title: Molecular mechanism of constitutively active Rab11A was revealed by crystal structure of Rab11A S20V.
abstract: Rab11A is a small GTP-binding protein involved in the regulation of vesicle trafficking during recycling of endosomes. Substitution of S20 to V (S20V) at Rab11A inhibits the GTP hydrolysis activity of Rab11A. This mutation is known to be constitutively in an active form. Here, we report the crystal structure of the human Rab11A S20V mutant form complexed with GTP at a resolution of 2.4 Å. Without adding any substrate, Rab11A contained non-hydrolyzed natural substrate GTP in the nucleotide binding pocket with Mg(2+). In our observations, substituted V20 of Rab11A was found to interfere with proper localization of the water molecule, which mediated GTP hydrolysis, resulting in GTP being locked in an active form of Rab11A S20V.
authors.affiliation: School of Biotechnology and Graduate School of Biochemistry at Yeungnam University, Gyeongsan, South Korea.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Department of Physiology, Department of Biomedical Sciences, and Institute of Dermatological Science, Seoul National University College of Medicine, South Korea.
authors.forename: Young-Cheul
authors.initials: YC
authors.lastname: Shin
authors.affiliation: School of Biotechnology and Graduate School of Biochemistry at Yeungnam University, Gyeongsan, South Korea.
authors.forename: Jong Hwan
authors.initials: JH
authors.lastname: Yoon
authors.affiliation: School of Biotechnology and Graduate School of Biochemistry at Yeungnam University, Gyeongsan, South Korea.
authors.forename: Chang Min
authors.initials: CM
authors.lastname: Kim
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, Inchon, South Korea.
authors.forename: Jun Hyuck
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Physiology, Department of Biomedical Sciences, and Institute of Dermatological Science, Seoul National University College of Medicine, South Korea.
authors.forename: Ju-Hong
authors.initials: JH
authors.lastname: Jeon
authors.affiliation: School of Biotechnology and Graduate School of Biochemistry at Yeungnam University, Gyeongsan, South Korea.
authors.forename: Hyun Ho
authors.initials: HH
authors.lastname: Park
mesh_terms: D019943:Amino Acid Substitution; D020134:Catalytic Domain / Q000235:genetics; D018360:Crystallography, X-Ray; D004789:Enzyme Activation; D006150:Guanine Nucleotides / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D008274:Magnesium / Q000378:metabolism; D008958:Models, Molecular; D008970:Molecular Weight; D016297:Mutagenesis, Site-Directed; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014867:Water / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000099193:rab11 GTP-Binding Proteins
chemical_list: D006150:Guanine Nucleotides; D006160:Guanosine Triphosphate; D008274:Magnesium; D011994:Recombinant Proteins; D014867:Water; D020691:rab GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins
keywords: Rab11; crystal structure; membrane trafficking; small G protein