The Gemin6-Gemin7 heterodimer from the survival of motor neurons complex has an Sm protein-like structure.
The survival of motor neurons (SMN) protein, product of the disease gene of the common neurodegenerative disease spinal muscular atrophy, is part of the large multiprotein "SMN complex." The SMN complex functions as an assembly machine for small nuclear ribonucleoproteins (snRNPs)-the major components of the spliceosome. Here, we report the crystal structure of two components of the human SMN complex, Gemin6 and Gemin7. Although Gemin6 and Gemin7 have no significant sequence similarity with Sm proteins, both adopt canonical Sm folds. Moreover, Gemin6 and Gemin7 exist as a heterodimer, and interact with each other via an interface similar to that which mediates interactions among the Sm proteins. Together with binding experiments that show that the Gemin6/Gemin7 complex binds to Sm proteins, these findings provide a framework for considering how the SMN complex, with Gemin6 and Gemin7 as tools, might organize Sm proteins for formation of Sm rings on snRNA targets.
Ma
Yingli
Y
Department of Biochemistry and Biophysics, Howard Hughes Medical Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
Dostie
Josée
J
Dreyfuss
Gideon
G
Van Duyne
Gregory D
GD
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry* / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D019281:Dimerization; D006801:Humans; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009046:Motor Neurons / Q000737:chemistry*; D046912:Multiprotein Complexes / Q000737:chemistry; D009687:Nuclear Proteins / Q000737:chemistry* / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism; D011485:Protein Binding; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism; D055532:SMN Complex Proteins; D017386:Sequence Homology, Amino Acid; D017381:Spliceosomes / Q000737:chemistry; D055672:Static Electricity; D014357:Trypsin / Q000494:pharmacology; D014961:X-Ray Diffraction
D002352:Carrier Proteins; D046912:Multiprotein Complexes; D009687:Nuclear Proteins; D017411:Ribonucleoproteins, Small Nuclear; D055532:SMN Complex Proteins; D014357:Trypsin; C450836:GEMIN6 protein, human; C466231:GEMIN7 protein, human