title: Crystal structure of translation initiation factor 5B from the crenarchaeon Aeropyrum pernix.
abstract: Initiation factor 5B (IF5B) is a universally conserved translational GTPase that catalyzes ribosomal subunit joining. In eukaryotes, IF5B directly interacts via a groove in its domain IV with initiation factor 1A (IF1A), another universally conserved initiation factor, to accomplish efficient subunit joining. Here, we have determined the first structure of a crenarchaeal IF5B, which revealed that the archaea-specific region of IF5B (helix α15) binds and occludes the groove of domain IV. Therefore, archaeal IF5B cannot access IF1A in the same manner as eukaryotic IF5B. This fact suggests that different relationships between IF5B and IF1A exist in archaea and eukaryotes.
authors: Department of Food and Life Sciences, Graduate School of Science and Technology, Niigata University, Japan.
authors: Ryo
authors: R
authors: Murakami
authors: Center for Transdisciplinary Research, Niigata University, Japan.
authors: Tomohiro
authors: T
authors: Miyoshi
authors: Department of Food and Life Sciences, Graduate School of Science and Technology, Niigata University, Japan.|Department of Biology, Faculty of Science, Niigata University, Japan.
authors: Toshio
authors: T
authors: Uchiumi
authors: Department of Food and Life Sciences, Graduate School of Science and Technology, Niigata University, Japan.|Department of Biology, Faculty of Science, Niigata University, Japan.
authors: Kosuke
authors: K
authors: Ito
mesh_terms: D041522:Aeropyrum / Q000737:chemistry / Q000235:genetics*; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure*; D018360:Crystallography, X-Ray; D039642:Eukaryotic Initiation Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure*; D008958:Models, Molecular; D011487:Protein Conformation
chemical_list: D019843:Archaeal Proteins; D039642:Eukaryotic Initiation Factors; C451459:eukaryotic initiation factor-5B
keywords: GTP hydrolysis; X-ray crystallography; molecular evolution; ribosomal subunit joining; translational GTPase