TY - JOUR
T1 - Solution structure of CCP modules 10-12 illuminates functional architecture of the complement regulator, factor H
AU - Makou, Elisavet
AU - Mertens, Haydyn D T
AU - Maciejewski, Mateusz
AU - Soares, Dinesh C
AU - Matis, Ilias
AU - Schmidt, Christoph Q
AU - Herbert, Andrew P
AU - Svergun, Dmitri I
AU - Barlow, Paul N
N1 - This work was funded by the Wellcome Trust grants 073131 and 085025. H.D.T.M. was supported by a fellowship from the European Molecular Biology Laboratory Interdisciplinary Postdoctoral Programme. Use of the Edinburgh Protein Production Facility was supported by The Wellcome Trust, the Scottish University Life Sciences Alliance and the Biotechnology and Biological Sciences Research Council.
PY - 2012
Y1 - 2012
N2 - The 155-kDa plasma glycoprotein factor H (FH), which consists of 20 complement-control protein modules (CCPs), protects self-tissue but not foreign organisms from damage by the complement cascade. Protection is achieved by selective engagement of FH, via CCPs 1-4, CCPs 6-8 and CCPs 19-20, with polyanion-rich host surfaces that bear covalently attached, activation-specific, fragments of complement component C3. The role of intervening CCPs 9-18 in this process is obscured by lack of structural knowledge. We have concatenated new high-resolution solution structures of overlapping recombinant CCP pairs, 10-11 and 11-12, to form a three-dimensional structure of CCPs 10-12 and validated it by small-angle X-ray scattering of the recombinant triple module fragment. Superimposing CCP 12 of this 10-12 structure with CCP 12 from the previously solved CCPs 12-13 structure yielded an S-shaped structure for CCPs 10-13 in which modules are tilted by 80-110° with respect to immediate neighbours, but the bend between CCPs 10 and 11 is counter to the arc traced by CCPs 11-13. Including this four-CCP structure in interpretation of scattering data for the longer recombinant segments, CCPs 10-15 and 8-15, implied flexible attachment of CCPs 8-9 to CCP 10, but compact and intimate arrangements of CCP 14 with CCPs 12, 13 and 15. Taken together with difficulties in recombinant production of module pairs 13-14 and 14-15, the aberrant structure of CCP 13, and the variability of 13-14 linker sequences amongst orthologues, a structural dependency of CCP 14 on its neighbours is suggested; this has implications for the FH mechanism.
AB - The 155-kDa plasma glycoprotein factor H (FH), which consists of 20 complement-control protein modules (CCPs), protects self-tissue but not foreign organisms from damage by the complement cascade. Protection is achieved by selective engagement of FH, via CCPs 1-4, CCPs 6-8 and CCPs 19-20, with polyanion-rich host surfaces that bear covalently attached, activation-specific, fragments of complement component C3. The role of intervening CCPs 9-18 in this process is obscured by lack of structural knowledge. We have concatenated new high-resolution solution structures of overlapping recombinant CCP pairs, 10-11 and 11-12, to form a three-dimensional structure of CCPs 10-12 and validated it by small-angle X-ray scattering of the recombinant triple module fragment. Superimposing CCP 12 of this 10-12 structure with CCP 12 from the previously solved CCPs 12-13 structure yielded an S-shaped structure for CCPs 10-13 in which modules are tilted by 80-110° with respect to immediate neighbours, but the bend between CCPs 10 and 11 is counter to the arc traced by CCPs 11-13. Including this four-CCP structure in interpretation of scattering data for the longer recombinant segments, CCPs 10-15 and 8-15, implied flexible attachment of CCPs 8-9 to CCP 10, but compact and intimate arrangements of CCP 14 with CCPs 12, 13 and 15. Taken together with difficulties in recombinant production of module pairs 13-14 and 14-15, the aberrant structure of CCP 13, and the variability of 13-14 linker sequences amongst orthologues, a structural dependency of CCP 14 on its neighbours is suggested; this has implications for the FH mechanism.
U2 - 10.1016/j.jmb.2012.09.013
DO - 10.1016/j.jmb.2012.09.013
M3 - Article
C2 - 23017427
VL - 424
SP - 295
EP - 312
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 5
ER -