1t6h
Crystal Structure T4 Lysozyme incorporating an unnatural amino acid p-iodo-L-phenylalanine at position 153
Overview
A recently developed method makes it possible to genetically encode unnatural amino acids with diverse physical, chemical or biological properties in Escherichia coli and yeast. We now show that this technology can be used to efficiently and site-specifically incorporate p-iodo-L-phenylalanine (iodoPhe) into proteins in response to an amber TAG codon. The selective introduction of the anomalously scattering iodine atom into proteins should facilitate single-wavelength anomalous dispersion experiments on in-house X-ray sources. To illustrate this, we generated a Phe153 --> iodoPhe mutant of bacteriophage T4 lysozyme and determined its crystal structure using considerably less data than are needed for the equivalent experiment with cysteine and methionine. The iodoPhe residue, although present in the hydrophobic core of the protein, did not perturb the protein structure in any meaningful way. The ability to selectively introduce this and other heavy atom-containing amino acids into proteins should facilitate the structural study of proteins.
About this Structure
1T6H is a Single protein structure of sequence from Enterobacteria phage t4. Full crystallographic information is available from OCA.
Reference
The site-specific incorporation of p-iodo-L-phenylalanine into proteins for structure determination., Xie J, Wang L, Wu N, Brock A, Spraggon G, Schultz PG, Nat Biotechnol. 2004 Oct;22(10):1297-301. Epub 2004 Sep 19. PMID:15378068 Page seeded by OCA on Sat May 3 09:35:27 2008