title: Crystal structures of receptors involved in small molecule transport across membranes.
abstract: This paper briefly reviews contemporary protein crystallography and focuses on six receptor proteins of membrane-intrinsic ATP binding cassette (ABC) transporters. Three of these receptors are specific for carbohydrates and three for amino acids. The receptor GacH of the transporter GacFGH from Streptomyces glaucescens is specific for acarbose and its homologs, and MalE of Salmonella typhimurium is specific for maltose but also forms a complex with acarbose, and the third receptor is the highly specific d-galactose receptor AcbH of the transporter AcbFGH from Actinoplanes sp. Concerning the receptors for amino acids, ArtJ belongs to the ArtJ-(MP)(2) transporter of Geobacillus stearotermophilus and recognizes and binds to positively charged arginine, lysine, and histidine with different sizes of side chains, contrasting the receptors Ngo0372 and Ngo2014 from Neisseria gonorrhaeae that are highly specific for cystine and cysteine, respectively. The differences in the rather unspecific receptors GacH, MalE and ArtJ are compared with the highly specific receptors AcbH, Ngo0372 and Ngo2014.
authors.affiliation: Institut für Chemie und Biochemie, Abteilung Kristallographie, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany.
authors.forename: Haydar
authors.initials: H
authors.lastname: Bulut
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Ma
authors.forename: Sebastien
authors.initials: S
authors.lastname: Moniot
authors.forename: Wolfram
authors.initials: W
authors.lastname: Saenger
authors.forename: Erwin
authors.initials: E
authors.lastname: Schneider
authors.forename: Ardeschir
authors.initials: A
authors.lastname: Vahedi-Faridi
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000737:chemistry* / Q000378:metabolism* / Q000502:physiology; D020909:Acarbose / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000502:physiology; D001693:Biological Transport, Active / Q000502:physiology; D018360:Crystallography, X-Ray / Q000379:methods* / Q000639:trends; D005690:Galactose / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000502:physiology; D021381:Protein Transport / Q000502:physiology
chemical_list: D018528:ATP-Binding Cassette Transporters; D000596:Amino Acids; D001426:Bacterial Proteins; D020909:Acarbose; D005690:Galactose