Structural highlights
Function
[TIM44_HUMAN] Essential component of the PAM complex, a complex required for the translocation of transit peptide-containing proteins from the inner membrane into the mitochondrial matrix in an ATP-dependent manner. Recruits mitochondrial HSP70 to drive protein translocation into the matrix using ATP as an energy source.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Familial oncocytic thyroid carcinoma is associated with a missense mutation, P308Q, in the C-terminal domain of Tim44. Tim44 is the mitochondrial inner-membrane translocase subunit and it functions as a membrane anchor for the mitochondrial heat-shock protein 70 (mtHsp70). Here, the crystal structure of the human Tim44 C-terminal domain complexed with pentaethylene glycol has been determined at 1.9 A resolution. The overall structure resembles that of the nuclear transport factor 2-like domain. In the crystal structure, pentaethylene glycol molecules are associated at two potential membrane-binding sites: the large hydrophobic cavity and the highly conserved loop between the alpha1 and alpha2 helices near Pro308. A comparison with the yeast homolog revealed that lipid binding induces conformational changes around the alpha1-alpha2 loop, leading to slippage of the alpha1 helix along the large beta-sheet. These changes may play important roles in the translocation of polypeptides across the mitochondrial inner membrane.
Structure of the human Tim44 C-terminal domain in complex with pentaethylene glycol: ligand-bound form.,Handa N, Kishishita S, Morita S, Akasaka R, Jin Z, Chrzas J, Chen L, Liu ZJ, Wang BC, Sugano S, Tanaka A, Terada T, Shirouzu M, Yokoyama S Acta Crystallogr D Biol Crystallogr. 2007 Dec;63(Pt 12):1225-34. Epub 2007, Nov 16. PMID:18084070[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Handa N, Kishishita S, Morita S, Akasaka R, Jin Z, Chrzas J, Chen L, Liu ZJ, Wang BC, Sugano S, Tanaka A, Terada T, Shirouzu M, Yokoyama S. Structure of the human Tim44 C-terminal domain in complex with pentaethylene glycol: ligand-bound form. Acta Crystallogr D Biol Crystallogr. 2007 Dec;63(Pt 12):1225-34. Epub 2007, Nov 16. PMID:18084070 doi:10.1107/S0907444907051463