title: Localization of prefoldin interaction sites in the hyperthermophilic group II chaperonin and correlations between binding rate and protein transfer rate.
abstract: Prefoldin is a molecular chaperone that captures a protein-folding intermediate and transfers it to a group II chaperonin for correct folding. The manner by which prefoldin interacts with a group II chaperonin is poorly understood. Here, we have examined the prefoldin interaction site in the archaeal group II chaperonin, comparing the interaction of two Thermococcus chaperonins and their mutants with Pyrococcus prefoldin by surface plasmon resonance. We show that the mutations of Lys250 and Lys256 of Thermococcus alpha chaperonin residues to Glu residues increase the affinity to Pyrococcus prefoldin to the level of Thermococcus beta chaperonin and Pyrococcus chaperonin, indicating that their Glu250 and Glu256 residues of the helical protrusion region are responsible for relatively stronger binding to Pyrococcus prefoldin than Thermococcus alpha chaperonin. Since the putative chaperonin binding sites in the distal ends of Pyrococcus prefoldin are rich in basic residues, electrostatic interaction seems to be important for their interaction. The substrate protein transfer rate from prefoldin correlates well with its affinity for chaperonin.
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Koganei-Shi, Tokyo, Japan.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Zako
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Murase
authors.forename: Ryo
authors.initials: R
authors.lastname: Iizuka
authors.forename: Takao
authors.initials: T
authors.lastname: Yoshida
authors.forename: Taro
authors.initials: T
authors.lastname: Kanzaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Ide
authors.forename: Mizuo
authors.initials: M
authors.lastname: Maeda
authors.forename: Takashi
authors.initials: T
authors.lastname: Funatsu
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yohda
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019843:Archaeal Proteins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D002417:Cattle; D018833:Chaperonins / Q000737:chemistry / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D019711:Pyrococcus / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D019712:Thermococcus / Q000737:chemistry / Q000378:metabolism
chemical_list: D019843:Archaeal Proteins; D018832:Molecular Chaperones; C112806:prefoldin; D049452:Green Fluorescent Proteins; D018833:Chaperonins