Solution structure of a membrane-anchored ubiquitin-fold (MUB) protein from Homo sapiens.
The protein Bc059385, whose solution structure is reported here, is the human representative of a recently identified family of membrane-anchored ubiquitin-fold (MUB) proteins. Analysis of their similarity to ubiquitin indicates that homologous amino acid residues in MUBs form a hydrophobic surface very similar to the recognition patch surrounding Ile-44 in ubiquitin. This suggests that MUBs may interact with proteins containing an alpha-helical motif similar to those of some ubiquitin binding domains. A disordered loop common to MUBs may also provide a second protein interaction site. From the available data, it is probable that this protein is prenylated and associated with the membrane. With <20% identity to ubiquitin, the MUB family further expands the sequence space that maps to the beta-grasp fold, and adds membrane localization to its list of functional roles.
de la Cruz
Norberto B
NB
Department of Biochemistry and Center for Eukaryotic Structural Genomics, Medical College of Wisconsin, Milwaukee 53226, USA.
Peterson
Francis C
FC
Lytle
Betsy L
BL
Volkman
Brian F
BF
D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D009682:Magnetic Resonance Spectroscopy; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D011485:Protein Binding; D017510:Protein Folding; D017368:Protein Prenylation; D012996:Solutions; D025801:Ubiquitin / Q000737:chemistry* / Q000378:metabolism
D008565:Membrane Proteins; D012996:Solutions; D025801:Ubiquitin