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Publication Abstract from PubMed

The members of the avidin protein family are well known for their high affinity towards d-biotin and their structural stability. These properties make avidins a valuable tool for various biotechnological applications. In the present study, two avidin-like biotin-binding proteins (named streptavidin C1 and C2) from Streptomyces cinnamonensis were newly identified while exploring antifungal proteins against Fusarium oxysporum f. sp. cucumerinum. Streptavidin C1 reveals a low correlation (a sequence identity of approximately 64%) with all known streptavidins, whereas streptavidin C2 shares a sequence identity of approximately 94% with other streptavidins. Here, the crystal structures of streptavidin C1 in the mature form and in complex with biotin at 2.1 and 2.5 A resolution, respectively, were assessed. The overall structures present similar tetrameric features with D 2 symmetry to other (strept)avidin structures. Interestingly, the long C-terminal region comprises a short alpha-helix (C-Lid; residues 169-179) and an extension C-terminal peptide (ECP; residues 180-191) which stretches into the biotin-binding sites of the same monomer. This ECP sequence (-(180)VTSANPPAS(188)-) is a newly defined biotin-binding site, which reduces the ability to bind to (strept)avidin family proteins. The novel streptavidin C1 could help in the development of an engineered tetrameric streptavidin with reduced biotin-binding capacity as well as other biomaterial tools.

Insights into the structure of mature streptavidin C1 from Streptomyces cinnamonensis reveal the self-binding of the extension C-terminal peptide to biotin-binding sites.,Jeon BJ, Kim S, Kim MS, Lee JH, Kim BS, Hwang KY IUCrJ. 2021 Jan 11;8(Pt 2):168-177. doi: 10.1107/S2052252520015675. eCollection, 2021 Mar 1. PMID:33708394^[1]

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