1xfo
From Proteopedia
|
Crystal Structure of an archaeal aminopeptidase
Overview
Protein turnover is an essential process in living cells. The degradation, of cytosolic polypeptides is mainly carried out by the proteasome, resulting in 7-9-amino acid long peptides. Further degradation is usually, carried out by energy-independent proteases like the tricorn protease from, Thermoplasma acidophilum. Recently, a novel tetrahedral-shaped dodecameric, 480-kDa aminopeptidase complex (TET) has been described in Haloarcula, marismortui that differs from the known ring- or barrel-shaped, self-compartmentalizing proteases. This complex is capable of degrading, most peptides down to amino acids. We present here the crystal structure, of the tetrahedral aminopeptidase homolog FrvX from Pyrococcus horikoshii., The monomer has a typical clan MH fold, as found for example in Aeromonas, proteolytica aminopeptidase, containing a dinuclear zinc active center., The quaternary structure is built by dimers with a length of 100 A that, form the edges of the tetrahedron. All 12 active sites are located on the, inside of the tetrahedron. Substrate access is granted by pores with a, maximal diameter of 10 A, allowing only small peptides and unfolded, proteins access to the active site.
About this Structure
1XFO is a Single protein structure of sequence from Pyrococcus horikoshii with ZN as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of a dodecameric tetrahedral-shaped aminopeptidase., Russo S, Baumann U, J Biol Chem. 2004 Dec 3;279(49):51275-81. Epub 2004 Sep 16. PMID:15375159
Page seeded by OCA on Sun Nov 25 02:04:06 2007
