6ovp

Publication Abstract from PubMed

Isolated or as a part of multidomain proteins, Sterol Carrier Protein 2 (SCP2) exhibits high affinity and broad specificity for different lipidic and hydrophobic compounds. A wealth of structural information on SCP2 domains in all forms of life is currently available; however, many aspects of its ligand binding activity are poorly understood. ylSCP2 is a well-characterized single domain SCP2 from the yeast Yarrowia lipolytica. Herein, we report the X-ray structure of unliganded ylSCP2 refined to 2.0 A resolution. Comparison with the previously solved liganded ylSCP2 structure unveiled a novel mechanism for binding site occlusion. The liganded ylSCP2 binding site is a large cavity with a volume of more than 800 A(3). In unliganded ylSCP2 the binding site is reduced to about 140 A(3). The obliteration is caused by a swing movement of the C-terminal alpha helix 5 and a subtle compaction of helices 2-4. Previous pairwise comparisons were between homologous SCP2 domains with a uncertain binding status. The reported unliganded ylSCP2 structure allows for the first time a fully controlled comparative analysis of the conformational effects of ligand occupation dispelling several doubts regarding the architecture of SCP2 binding site.

The structure of unliganded sterol carrier protein 2 from Yarrowia lipolytica unveils a mechanism for binding site occlusion.,Gianotti AR, Klinke S, Ermacora MR J Struct Biol. 2020 Dec 2;213(1):107675. doi: 10.1016/j.jsb.2020.107675. PMID:33278583^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.