Title |
Structural Model of a Malonyl-CoA-binding Site of Carnitine Octanoyltransferase and Carnitine Palmitoyltransferase I MUTATIONAL ANALYSIS OF A MALONYL-CoA AFFINITY DOMAIN*
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Published in |
Journal of Biological Chemistry, January 2002
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DOI | 10.1074/jbc.m111628200 |
Pubmed ID | |
Authors |
Montserrat Morillas, Paulino Gómez-Puertas, Blanca Rubı́, Josep Clotet, Joaquı́n Ariño, Alfonso Valencia, Fausto G. Hegardt, Dolors Serra, Guillermina Asins |
Abstract |
Carnitine octanoyltransferase (COT) and carnitine palmitoyltransferase (CPT) I, which facilitate the transport of medium- and long-chain fatty acids through the peroxisomal and mitochondrial membranes, are physiologically inhibited by malonyl-CoA. Using an "in silico" macromolecular docking approach, we built a model in which malonyl-CoA could be attached near the catalytic core. This disrupts the positioning of the acyl-CoA substrate in the channel in the model reported for both proteins (Morillas, M., Gómez-Puertas, P., Roca, R., Serra, D., Asins, G., Valencia, A., and Hegardt, F. G. (2001) J. Biol. Chem. 276, 45001-45008). The putative malonyl-CoA domain contained His(340), implicated together with His(131) in COT malonyl-CoA sensitivity (Morillas, M., Clotet, J., Rubi, B., Serra, D., Asins, G., Ariño, J., and Hegardt F. G. (2000) FEBS Lett. 466, 183-186). When we mutated COT His(131) the IC(50) increased, and malonyl-CoA competed with the substrate decanoyl-CoA. Mutation of COT Ala(332), present in the domain 8 amino acids away from His(340), decreased the malonyl-CoA sensitivity of COT. The homologous histidine and alanine residues of L-CPT I, His(277), His(483), and Ala(478) were also mutated, which decreased malonyl-CoA sensitivity. Natural mutation of Pro(479), which is also located in the malonyl-CoA predicted site, to Leu in a patient with human L-CPT I hereditary deficiency, modified malonyl-CoA sensitivity. We conclude that this malonyl-CoA domain is present in both COT and L-CPT I proteins and might be the site at which malonyl-CoA interacts with the substrate acyl-CoA. Other malonyl-CoA non-inhibitable members of the family, CPT II and carnitine acetyltransferase, do not contain this domain. |
Mendeley readers
Geographical breakdown
Country | Count | As % |
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Spain | 1 | 2% |
United States | 1 | 2% |
Unknown | 40 | 95% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Student > Ph. D. Student | 10 | 24% |
Researcher | 6 | 14% |
Professor | 5 | 12% |
Professor > Associate Professor | 4 | 10% |
Other | 3 | 7% |
Other | 5 | 12% |
Unknown | 9 | 21% |
Readers by discipline | Count | As % |
---|---|---|
Agricultural and Biological Sciences | 18 | 43% |
Biochemistry, Genetics and Molecular Biology | 7 | 17% |
Medicine and Dentistry | 3 | 7% |
Chemistry | 2 | 5% |
Pharmacology, Toxicology and Pharmaceutical Science | 1 | 2% |
Other | 1 | 2% |
Unknown | 10 | 24% |