5e5q

Publication Abstract from PubMed

Proteins from the GASA/snakin superfamily are common in plant proteomes and have diverse functions, including hormonal crosstalk, development, and defense. One 63-residue member of this family, snakin-1, an antimicrobial protein from potatoes, has previously been chemically synthesized in a fully active form. Herein the 1.5 A structure of snakin-1, determined by a novel combination of racemic protein crystallization and radiation-damage-induced phasing (RIP), is reported. Racemic crystals of snakin-1 and quasi-racemic crystals incorporating an unnatural 4-iodophenylalanine residue were prepared from chemically synthesized d- and l-proteins. Breakage of the C-I bonds in the quasi-racemic crystals facilitated structure determination by RIP. The crystal structure reveals a unique protein fold with six disulfide crosslinks, presenting a distinct electrostatic surface that may target the protein to microbial cell surfaces.

Radiation Damage and Racemic Protein Crystallography Reveal the Unique Structure of the GASA/Snakin Protein Superfamily.,Yeung H, Squire CJ, Yosaatmadja Y, Panjikar S, Lopez G, Molina A, Baker EN, Harris PW, Brimble MA Angew Chem Int Ed Engl. 2016 May 4. doi: 10.1002/anie.201602719. PMID:27145301^[1]

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