Three-dimensional models of human 2'-5' oligoadenylate synthetases: a new computational method for reconstructing an enzyme assembly.

Background: 2'-5' Oligoadenylate synthetases are interferon-induced enzymes important for antiviral cell defense. Tetramer formation of human OAS1 is essential for the catalytic activity of the enzyme. However, no structure of any oligomeric OAS1 protein has yet been solved and the structural organization of the catalytically active tetramers is not known.

Computed energetics of nucleotides in spatial ribozyme structures: an accurate identification of functional regions from structure.

Ribozymes are functionally diverse RNA molecules with intrinsic catalytic activity. Multiple structural and biochemical studies are required to establish which nucleotide bases are involved in the catalysis. The relative energetic properties of the nucleotide bases have been analyzed in a set of the known ribozyme structures.