1nig

[[Image:1nig.gif|left|200px]]<br /><applet load="1nig" size="450" color="white" frame="true" align="right" spinBox="true"

caption="1nig, resolution 2.00&Aring;" />

'''2.0 A Structure of Protein of Unknown Function from Thermoplasma acidophilum'''<br />

==Overview==

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.

 

==About this Structure==

1NIG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermoplasma_acidophilum Thermoplasma acidophilum]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1NIG OCA].

 

==Reference==

Crystal structure of the hypothetical protein TA1238 from Thermoplasma acidophilum: a new type of helical super-bundle., Sanishvili R, Pennycooke M, Gu J, Xu X, Joachimiak A, Edwards AM, Christendat D, J Struct Funct Genomics. 2004;5(4):231-40. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=15704011 15704011]

[[Category: Single protein]]

[[Category: Christendat, D.]]

[[Category: Edwards, A.]]

[[Category: MCSG, Midwest.Center.for.Structural.Genomics.]]

[[Category: Sanishvili, R.]]