TY  - JOUR
A1  - Tripp, Joanna
A1  - Hahn, Alexander
A1  - König, Patrick
A1  - Flinner, Nadine
A1  - Bublak, Daniela
A1  - Brouwer, Eva-Maria
A1  - Ertel, Franziska
A1  - Mirus, Oliver
A1  - Sinning, Irmgard
A1  - Tews, Ivo
A1  - Schleiff, Enrico
T1  - Structure and conservation of the periplasmic targeting factor Tic22 protein from plants and cyanobacteria
T2  - Journal of biological chemistry
N2  - Mitochondria and chloroplasts are of endosymbiotic origin. Their integration into cells entailed the development of protein translocons, partially by recycling bacterial proteins. We demonstrate the evolutionary conservation of the translocon component Tic22 between cyanobacteria and chloroplasts. Tic22 in Anabaena sp. PCC 7120 is essential. The protein is localized in the thylakoids and in the periplasm and can be functionally replaced by a plant orthologue. Tic22 physically interacts with the outer envelope biogenesis factor Omp85 in vitro and in vivo, the latter exemplified by immunoprecipitation after chemical cross-linking. The physical interaction together with the phenotype of a tic22 mutant comparable with the one of the omp85 mutant indicates a concerted function of both proteins. The three-dimensional structure allows the definition of conserved hydrophobic pockets comparable with those of ClpS or BamB. The results presented suggest a function of Tic22 in outer membrane biogenesis.
Background: Although Tic22 is involved in protein import into chloroplasts, the function in cyanobacteria is unknown.
Results: Cyanobacterial Tic22 is required for OM biogenesis, shares structural features with chaperones, and can be substituted by plant Tic22.
Conclusion: Tic22, involved in outer membrane biogenesis, is functionally conserved in cyanobacteria and plants.
Significance: The findings are important for the understanding of periplasmic protein transport.
KW  - Cell Wall
KW  - Chaperone Chaperonin
KW  - Crystal Structure
KW  - Cyanobacteria
KW  - Protein Translocation
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/76643
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-766430
SN  - 0021-9258
VL  - 287.2012
IS  - 29
SP  - 24164
EP  - 24173
PB  - American Society for Biochemistry and Molecular Biology Publications
CY  - Bethesda, Md
ER  -