1M5Q

Crystal structure of a novel Sm-like archaeal protein from Pyrobaculum aerophilum

Summary for 1M5Q

• Entry DOI: 10.2210/pdb1m5q/pdb
• Related: 1D3B 1I4K 1I8F 1JBM
• Descriptor: small nuclear ribonucleoprotein homolog, CADMIUM ION, SODIUM ION, ... (6 entities in total)
• Functional Keywords: ob-like fold, b-sheet toroid, 14-mer, cadmium-binding site, translation
• Biological source: Pyrobaculum aerophilum
• Total number of polymer chains: 28
• Total formula weight: 425487.61

Authors

Mura, C.,Phillips, M.,Kozhukhovsky, A.,Eisenberg, D. (deposition date: 2002-07-09, release date: 2003-03-18, Last modification date: 2024-10-30)

Primary citation

Mura, C.,Phillips, M.,Kozhukhovsky, A.,Eisenberg, D.
Structure and assembly of an augmented Sm-like archaeal protein 14-mer
Proc.Natl.Acad.Sci.USA, 100:4539-4544, 2003

PubMed Abstract: To better understand the roles of Sm proteins in forming the cores of many RNA-processing ribonucleoproteins, we determined the crystal structure of an atypical Sm-like archaeal protein (SmAP3) in which the conserved Sm domain is augmented by a previously uncharacterized, mixed alpha/beta C-terminal domain. The structure reveals an unexpected SmAP3 14-mer that is perforated by a cylindrical pore and is bound to 14 cadmium (Cd(2+)) ions. Individual heptamers adopt either "apical" or "equatorial" conformations that chelate Cd(2+) differently. SmAP3 forms supraheptameric oligomers (SmAP3)(n = 7,14,28) in solution, and assembly of the asymmetric 14-mer is modulated by differential divalent cation-binding in apical and equatorial subunits. Phylogenetic and sequence analyses substantiate SmAP3s as a unique subset of SmAPs. These results distinguish SmAP3s from other Sm proteins and provide a model for the structure and properties of Sm proteins >100 residues in length, e.g., several human Sm proteins.

PubMed: 12668760
DOI: 10.1073/pnas.0538042100

Experimental method

X-RAY DIFFRACTION (2 Å)