title: Insights into functional aspects of centrins from the structure of N-terminally extended mouse centrin 1.
abstract: Centrins are members of the family of Ca(2+)-binding EF-hand proteins. In photoreceptor cells, centrin isoform 1 is specifically localized in the non-motile cilium. This connecting cilium links the light-sensitive outer segment with the biosynthetic active inner segment of the photoreceptor cell. All intracellular exchanges between these compartments have to occur through this cilium. Three-dimensional structures of centrins from diverse organisms are known, showing that the EF-hand motifs of the N-terminal domains adopt closed conformations, while the C-terminal EF-hand motifs have open conformations. The crystal structure of an N-terminally extended mouse centrin 1 (MmCen1-L) resembles the overall structure of troponin C in its two Ca(2+) bound form. Within the N-terminal extension in MmCen1-L, residues W24 and R25 bind to the C-terminal domain of centrin 1 in a target-protein-like geometry. Here, we discuss this binding mode in connection with putative interaction sites of the target-protein transducin and the self-assembly of centrins.
authors.affiliation: Institut für Medizinische Physik und Biophysik, Charité-Universitätsmedizin Berlin, Ziegelstr. 5-9, D-10098 Berlin, Germany.
authors.forename: Jung Hee
authors.initials: JH
authors.lastname: Park
authors.forename: Alexander
authors.initials: A
authors.lastname: Pulvermüller
authors.forename: Patrick
authors.initials: P
authors.lastname: Scheerer
authors.forename: Sebastian
authors.initials: S
authors.lastname: Rausch
authors.forename: Andreas
authors.initials: A
authors.lastname: Giessl
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Höhne
authors.forename: Uwe
authors.initials: U
authors.lastname: Wolfrum
authors.forename: Klaus Peter
authors.initials: KP
authors.lastname: Hofmann
authors.forename: Oliver Peter
authors.initials: OP
authors.lastname: Ernst
authors.forename: Hui-Woog
authors.initials: HW
authors.lastname: Choe
authors.forename: Norbert
authors.initials: N
authors.lastname: Krauss
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D002923:Cilia / Q000378:metabolism*; D020832:EF Hand Motifs; D006801:Humans; D051379:Mice; D010786:Photoreceptor Cells / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D017385:Sequence Homology; D013329:Structure-Activity Relationship; D020079:Terminal Repeat Sequences
chemical_list: D002135:Calcium-Binding Proteins; D002118:Calcium