3bks
Crystal Structure of Sterol Carrier Protein-2 like-3 (SCP2-L3) from Aedes Aegypti
Structural highlights
FunctionEvolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe sterol carrier protein-2 like 3 gene (AeSCP-2L3), a new member of the SCP-2 protein family, is identified from the yellow fever mosquito, Aedes aegypti. The predicted molecular weight of AeSCP-2L3 is 13.4 kDa with a calculated pI of 4.98. AeSCP-2L3 transcription occurs in the larval feeding stages and the mRNA levels decrease in pupae and adults. The highest levels of AeSCP-2L3 gene expression are found in the body wall, and possibly originated in the fat body. This is the first report of a mosquito SCP-2-like protein with prominent expression in tissue other than the midgut. The X-ray protein crystal structure of AeSCP-2L3 reveals a bound C16 fatty acid whose acyl tail penetrates deeply into a hydrophobic cavity. Interestingly, the ligand-binding cavity is slightly larger than previously described for AeSCP-2 (Dyer et al. J Biol Chem 278:39085-39091, 2003) and AeSCP-2L2 (Dyer et al. J Lipid Res M700460-JLR200, 2007). There are also an additional 10 amino acids in SCP-2L3 that are not present in other characterized mosquito SCP-2s forming an extended loop between beta 3 and beta 4. Otherwise, the protein backbone is exceedingly similar to other SCP-2 and SCP-2-like proteins. In contrast to this observed high structural homology of members in the mosquito SCP2 family, the amino acid sequence identity between the members is less than 30%. The results from structural analysis imply that there have been evolutionary constraints that favor the SCP-2 C(alpha) backbone fold while the specificity of ligand binding can be altered. Characterization of the yellow fever mosquito sterol carrier protein-2 like 3 gene and ligand-bound protein structure.,Dyer DH, Vyazunova I, Lorch JM, Forest KT, Lan Q Mol Cell Biochem. 2009 Jun;326(1-2):67-77. Epub 2009 Jan 7. PMID:19130179[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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