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1ult
From Proteopedia
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Crystal structure of tt0168 from Thermus thermophilus HB8
Overview
Long chain fatty acyl-CoA synthetases are responsible for fatty acid, degradation as well as physiological regulation of cellular functions via, the production of long chain fatty acyl-CoA esters. We report the first, crystal structures of long chain fatty acyl-CoA synthetase homodimer, (LC-FACS) from Thermus thermophilus HB8 (ttLC-FACS), including complexes, with the ATP analogue adenosine 5'-(beta,gamma-imido) triphosphate, (AMP-PNP) and myristoyl-AMP. ttLC-FACS is a member of the adenylate, forming enzyme superfamily that catalyzes the ATP-dependent acylation of, fatty acid in a two-step reaction. The first reaction step was shown to, propagate in AMP-PNP complex crystals soaked with myristate solution., Myristoyl-AMP was identified as the intermediate. The AMP-PNP and the, myristoyl-AMP complex structures show an identical closed conformation of, the small C-terminal domains, whereas the uncomplexed form shows a variety, of open conformations. Upon ATP binding, the fatty acid-binding tunnel, gated by an aromatic residue opens to the ATP-binding site. The gated, fatty acid-binding tunnel appears only to allow one-way movement of the, fatty acid during overall catalysis. The protein incorporates a, hydrophobic branch from the fatty acid-binding tunnel that is responsible, for substrate specificity. Based on these high resolution crystal, structures, we propose a unidirectional Bi Uni Uni Bi Ping-Pong mechanism, for the two-step acylation by ttLC-FACS.
About this Structure
1ULT is a Single protein structure of sequence from Thermus thermophilus with CIT as ligand. Active as Long-chain-fatty-acid--CoA ligase, with EC number 6.2.1.3 Full crystallographic information is available from OCA.
Reference
Structural basis of the substrate-specific two-step catalysis of long chain fatty acyl-CoA synthetase dimer., Hisanaga Y, Ago H, Nakagawa N, Hamada K, Ida K, Yamamoto M, Hori T, Arii Y, Sugahara M, Kuramitsu S, Yokoyama S, Miyano M, J Biol Chem. 2004 Jul 23;279(30):31717-26. Epub 2004 May 15. PMID:15145952
Page seeded by OCA on Sun Nov 25 04:11:17 2007
Categories: Long-chain-fatty-acid--CoA ligase | Single protein | Thermus thermophilus | Ago, H. | Arii, Y. | Hamada, K. | Hisanaga, Y. | Hori, T. | Ida, K. | Kanda, H. | Kuramitsu, S. | Miyano, M. | Nakatsu, T. | RSGI, RIKEN.Structural.Genomics/Proteomics.Initiative. | Sugahara, M. | Yamamoto, M. | Yokoyama, S. | CIT | Ligase | Riken structural genomics/proteomics initiative | Rsgi | Structural genomics
