Crystal structure of a novel Sm-like protein of putative cyanophage origin at 2.60 A resolution.
Das, D., Kozbial, P., Axelrod, H.L., Miller, M.D., McMullan, D., Krishna, S.S., Abdubek, P., Acosta, C., Astakhova, T., Burra, P., Carlton, D., Chen, C., Chiu, H.J., Clayton, T., Deller, M.C., Duan, L., Elias, Y., Elsliger, M.A., Ernst, D., Farr, C., Feuerhelm, J., Grzechnik, A., Grzechnik, S.K., Hale, J., Han, G.W., Jaroszewski, L., Jin, K.K., Johnson, H.A., Klock, H.E., Knuth, M.W., Kumar, A., Marciano, D., Morse, A.T., Murphy, K.D., Nigoghossian, E., Nopakun, A., Okach, L., Oommachen, S., Paulsen, J., Puckett, C., Reyes, R., Rife, C.L., Sefcovic, N., Sudek, S., Tien, H., Trame, C., Trout, C.V., van den Bedem, H., Weekes, D., White, A., Xu, Q., Hodgson, K.O., Wooley, J., Deacon, A.M., Godzik, A., Lesley, S.A., Wilson, I.A.(2009) Proteins 75: 296-307
- PubMed: 19173316 
- DOI: https://doi.org/10.1002/prot.22360
- Primary Citation of Related Structures:  
3BY7 - PubMed Abstract: 
ECX21941 represents a very large family (over 600 members) of novel, ocean metagenome-specific proteins identified by clustering of the dataset from the Global Ocean Sampling expedition. The crystal structure of ECX21941 reveals unexpected similarity to Sm/LSm proteins, which are important RNA-binding proteins, despite no detectable sequence similarity. The ECX21941 protein assembles as a homopentamer in solution and in the crystal structure when expressed in Escherichia coli and represents the first pentameric structure for this Sm/LSm family of proteins, although the actual oligomeric form in vivo is currently not known. The genomic neighborhood analysis of ECX21941 and its homologs combined with sequence similarity searches suggest a cyanophage origin for this protein. The specific functions of members of this family are unknown, but our structure analysis of ECX21941 indicates nucleic acid-binding capabilities and suggests a role in RNA and/or DNA processing.
Organizational Affiliation: 
Joint Center for Structural Genomics, 2 Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California, USA.