title: Structural similarity in the absence of sequence homology of the messenger RNA export factors Mtr2 and p15.
abstract: The association between Mtr2 and Mex67 is essential for the nuclear export of bulk messenger RNA in yeast. In metazoans, the analogous function is carried out by the TAP-p15 heterodimer. Whereas Mex67 and TAP are highly conserved proteins, their binding partners, Mtr2 and p15, share no sequence similarity, but are nevertheless functionally homologous. Here, we report the 2.8-A resolution crystal structure of Mtr2 in complex with the NTF2-like domain of Mex67. Mtr2 is a novel member of the NTF2-like family and interacts with Mex67, forming a complex with a similar structural architecture to that of TAP-p15. Mtr2 fulfils an analogous function to that of human p15 in maintaining the structural integrity of the heterodimer. In addition, Mtr2 presents a long internal loop, which contains residues that affect the export of the large ribosomal subunit.
authors.affiliation: European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117 Heidelberg, Germany.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Fribourg
authors.forename: Elena
authors.initials: E
authors.lastname: Conti
mesh_terms: D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019281:Dimerization; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism; D029543:Nucleocytoplasmic Transport Proteins / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D034443:RNA Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism; D017385:Sequence Homology
chemical_list: D002352:Carrier Proteins; C106898:MEX67 protein, S cerevisiae; D026901:Membrane Transport Proteins; C480169:Mtr2 protein, S cerevisiae; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; C503613:Nutf2 protein, mouse; C402484:Nxt1 protein, mouse; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins