1NM8

Structure of Human Carnitine Acetyltransferase: Molecular Basis for Fatty Acyl Transfer

Summary for 1NM8

• Entry DOI: 10.2210/pdb1nm8/pdb
• Descriptor: Carnitine O-acetyltransferase (2 entities in total)
• Functional Keywords: two equally sized domains, anti-parallel beta-strand, transferase
• Biological source: Homo sapiens (human)
• Cellular location: Endoplasmic reticulum (Potential). Isoform 1: Mitochondrion (Potential). Isoform 2: Peroxisome (Potential): P43155
• Total number of polymer chains: 1
• Total formula weight: 69902.87

Authors

Wu, D.,Govindasamy, L.,Lian, W.,Gu, Y.,Kukar, T.,Agbandje-McKenna, M.,McKenna, R. (deposition date: 2003-01-09, release date: 2003-03-11, Last modification date: 2024-02-14)

Primary citation

Wu, D.,Govindasamy, L.,Lian, W.,Gu, Y.,Kukar, T.,Agbandje-McKenna, M.,McKenna, R.
Structure of Human Carnitine Acetyltransferase. Molecular Basis for Fatty Acyl Transfer
J.Biol.Chem., 278:13159-13165, 2003

PubMed Abstract: Carnitine acyltransferases are a family of ubiquitous enzymes that play a pivotal role in cellular energy metabolism. We report here the x-ray structure of human carnitine acetyltransferase to a 1.6-A resolution. This structure reveals a monomeric protein of two equally sized alpha/beta domains. Each domain is shown to have a partially similar fold to other known but oligomeric enzymes that are also involved in group-transfer reactions. The unique monomeric arrangement of the two domains constitutes a central narrow active site tunnel, indicating a likely universal feature for all members of the carnitine acyltransferase family. Superimposition of the substrate complex of a related protein, dihydrolipoyl trans-acetylase, reveals that both substrates localize to the active site tunnel of human carnitine acetyltransferase, suggesting the location of the ligand binding sites for carnitine and coenzyme A. Most significantly, this structure provides critical insights into the molecular basis for fatty acyl chain transfer and a possible common mechanism among a wide range of acyltransferases utilizing a catalytic dyad.

PubMed: 12562770
DOI: 10.1074/jbc.M212356200

Experimental method

X-RAY DIFFRACTION (1.6 Å)