3kxc
Mutant transport protein
Structural highlights
FunctionTPPC3_HUMAN May play a role in vesicular transport from endoplasmic reticulum to Golgi. 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 PubMedBet3, a transport protein particle component involved in vesicular trafficking, contains a hydrophobic tunnel occupied by a fatty acid linked to cysteine 68. We reported that Bet3 has a unique self-palmitoylating activity. Here we show that mutation of arginine 67 reduced self-palmitoylation of Bet3, but the effect was compensated by increasing the pH. Thus, arginine helps to deprotonate cysteine such that it could function as a nucleophile in the acylation reaction which is supported by the structural analysis of non-acylated Bet3. Using fluorescence spectroscopy we show that long-chain acyl-CoAs bind with micromolar affinity to Bet3, whereas shorter-chain acyl-CoAs do not interact. Mutants with a deleted acylation site or a blocked tunnel bind to Pal-CoA, only the latter with slightly reduced affinity. Bet3 contains three binding sites for Pal-CoA, but their number was reduced to two in the mutant with an obstructed tunnel, indicating that Bet3 contains binding sites on its surface. Characterization of the self-palmitoylation activity of the transport protein particle component Bet3.,Kummel D, Walter J, Heck M, Heinemann U, Veit M Cell Mol Life Sci. 2010 Apr 6. PMID:20372964[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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