title: Lysine methylation as a routine rescue strategy for protein crystallization.
abstract: Crystallization remains a critical step in X-ray structure determination. Because it is not generally possible to rationally predict crystallization conditions, commercial screens have been developed which sample a wide range of crystallization space. While this approach has proved successful in many cases, a significant number of proteins fail to crystallize despite being soluble and monodispersed. It is established that chemical modification can facilitate the crystallization of otherwise intractable proteins. Here we describe a method for the reductive methylation of lysine residues which is simple, inexpensive, and efficient, and report on its application to ten proteins. We describe the effect of methylation on the physico-chemical properties of these proteins, and show that it led to diffraction-quality crystals from four proteins and structures for three that had hitherto proved refractory to crystallization. The method is suited to both low- and high-throughput laboratories.
authors.affiliation: Oxford Protein Production Facility, The Henry Wellcome Building for Genomic Medicine, Oxford University, Roosevelt Drive, Oxford OX3 7BN, United Kingdom.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Walter
authors.forename: Christoph
authors.initials: C
authors.lastname: Meier
authors.forename: Rene
authors.initials: R
authors.lastname: Assenberg
authors.forename: Kin-Fai
authors.initials: KF
authors.lastname: Au
authors.forename: Jingshan
authors.initials: J
authors.lastname: Ren
authors.forename: Anil
authors.initials: A
authors.lastname: Verma
authors.forename: Joanne E
authors.initials: JE
authors.lastname: Nettleship
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Owens
authors.forename: David I
authors.initials: DI
authors.lastname: Stuart
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Grimes
mesh_terms: D001408:Bacillus anthracis / Q000201:enzymology; D001671:Biochemistry / Q000379:methods*; D015331:Cohort Studies; D019295:Computational Biology; D003460:Crystallization / Q000295:instrumentation* / Q000379:methods*; D018360:Crystallography, X-Ray / Q000295:instrumentation / Q000379:methods; D005416:Flavivirus / Q000378:metabolism; D006801:Humans; D008239:Lysine / Q000737:chemistry*; D008745:Methylation; D008958:Models, Molecular; D006517:Murine hepatitis virus / Q000378:metabolism; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry
chemical_list: D011506:Proteins; D008239:Lysine