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2gbv
From Proteopedia
C6A/C111A/C57A/C146A holo CuZn Superoxide dismutase
Contents |
Overview
The gain of neurotoxic function in amyotrophic lateral sclerosis (ALS) has been linked to misfolding of the homodimeric enzyme Cu/Zn superoxide dismutase (SOD). Here, we present the crystal structure of fully cysteine-depleted human SOD (SOD(CallA)), representing a reduced, marginally stable intermediate on the folding pathway in vivo that has also been implicated as neurotoxic precursor state. A hallmark of this species is that it fails to dimerize and becomes trapped as a monomer in the absence of the active-site metals. The crystallographic data show that removal of the C57-C146 disulphide bond sets free the interface loop IV in the apo protein, whereas the same loop remains unaffected in the holo protein. Thus, the low dimerisation propensity of disulphide-reduced apoSOD seems to be of entropic origin due to increased loop flexibility in the monomeric state: in the disulphide-reduced holo protein this gain in configurational entropy upon splitting of the dimer interface is reduced by the metal coordination.
Disease
Known disease associated with this structure: Amyotrophic lateral sclerosis, due to SOD1 deficiency OMIM:[147450]
About this Structure
2GBV is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The coupling between disulphide status, metallation and dimer interface strength in Cu/Zn superoxide dismutase., Hornberg A, Logan DT, Marklund SL, Oliveberg M, J Mol Biol. 2007 Jan 12;365(2):333-42. Epub 2006 Sep 23. PMID:17070542 Page seeded by OCA on Sun May 4 04:55:51 2008
