1NIG

2.0 A Structure of Protein of Unknown Function from Thermoplasma acidophilum

Summary for 1NIG

• Entry DOI: 10.2210/pdb1nig/pdb
• Descriptor: hypothetical protein TA1238 (2 entities in total)
• Functional Keywords: structural genomics, four helixbundle, psi, protein structure initiative, midwest center for structural genomics, mcsg, unknown function
• Biological source: Thermoplasma acidophilum
• Total number of polymer chains: 1
• Total formula weight: 17921.28

Authors

Sanishvili, R.,Edwards, A.,Christendat, D.,Midwest Center for Structural Genomics (MCSG) (deposition date: 2002-12-23, release date: 2003-07-15, Last modification date: 2024-04-03)

Primary citation

Sanishvili, R.,Pennycooke, M.,Gu, J.,Xu, X.,Joachimiak, A.,Edwards, A.M.,Christendat, D.
Crystal structure of the hypothetical protein TA1238 from Thermoplasma acidophilum: a new type of helical super-bundle.
J.STRUCT.FUNCT.GENOM., 5:231-240, 2004

PubMed Abstract: The crystal structure of the hypothetical protein TA1238 from Thermoplasma acidophilum was solved with multiple-wavelength anomalous diffraction and refined at 2.0 A resolution. The molecule consists of a typical four-helix antiparallel bundle with overhand connection. However, its oligomerization into a trimer leads to a coiled "super-helix" which is novel for such bundles. Its central feature, a six-stranded coiled coil, is also novel for proteins. TA1238 does not have strong sequence homologues in databases, but shows strong structural similarity with some proteins in the Protein Data Bank. The function could not be inferred from the sequence but the structure, with some rearrangement, bears some resemblance to the active site region of cobalamin adenosyltransferase (TA1434). Specifically, TA1238 retains Arg104, which is structurally equivalent to functionally critical Arg119 of TA1434. For such conformational change, the overhand connection of TA1238 might need to be involved in a gating mechanism that might be modulated by ligands and/or by interactions with the physiological partners. This allowed us to hypothesize that TA1238 could be involved in cobalamin biosyntheses.

PubMed: 15704011
DOI: 10.1007/s10969-005-3789-1

Experimental method

X-RAY DIFFRACTION (2 Å)