title: Overexpression, purification and crystallization of the response regulator NsrR involved in nisin resistance.
abstract: A number of Gram-positive bacteria produce a class of bacteriocins called `lantibiotics'. These lantibiotics are ribosomally synthesized peptides that possess high antimicrobial activity against Gram-positive bacteria, including clinically challenging pathogens, and are therefore potential alternatives to antibiotics. All lantibiotic producer strains and some Gram-positive nonproducer strains express protein systems to circumvent a suicidal effect or to become resistant, respectively. Two-component systems consisting of a response regulator and a histidine kinase upregulate the expression of these proteins. One of the best-characterized lantibiotics is nisin, which is produced by Lactococcus lactis and possesses bactericidal activity against various Gram-positive bacteria, including some human pathogenic strains. Within many human pathogenic bacterial strains inherently resistant to nisin, a response regulator, NsrR, has been identified which regulates the expression of proteins involved in nisin resistance. In the present study, an expression and purification protocol was established for the NsrR protein from Streptococcus agalactiae COH1. The protein was successfully crystallized using the vapour-diffusion method, resulting in crystals that diffracted X-rays to 1.4 Å resolution.
authors.affiliation: Institute of Biochemistry, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
authors.forename: Sakshi
authors.initials: S
authors.lastname: Khosa
authors.affiliation: Crystal Farm and X-ray Facility, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Hoeppner
authors.affiliation: Protein Production Facility, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Kleinschrodt
authors.affiliation: Institute of Biochemistry, Heinrich-Heine-University, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
authors.forename: Sander H J
authors.initials: SH
authors.lastname: Smits
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D003460:Crystallization; D018360:Crystallography, X-Ray; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D008969:Molecular Sequence Data; D009561:Nisin / Q000494:pharmacology*; D013292:Streptococcus agalactiae / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D009561:Nisin; C102526:nisin A
keywords: X-ray analysis; lantibiotic; nisin; resistance; response regulator