The Paulinella chromatophore transit peptide part2 adopts a structural fold similar to the γ-glutamyl-cyclotransferase fold.

ABSTRACT: The chromatophores of the cercozoan amoeba Paulinella are photosynthetic organelles that evolved from a cyanobacterial endosymbiont. Many nucleus-encoded chromatophore-targeted proteins carry unusual N-terminal targeting signals termed crTPs, which are bipartite. crTPpart1 likely mediates trafficking through the secretory pathway and is cleaved off during import, but crTPpart2 remains attached to its cargo protein and its function is unknown. To unravel the functional role of crTPpart2, here we elucidated the structures of crTPpart2 from two different chromatophore-targeted proteins by X-ray crystallography at ∼2.3 Å resolution. Interestingly, the crTPpart2 of both proteins adopts a structural fold. Both structures share a conserved structured core and a flexible N-terminal arm. The struct

SUBMITTER: Klimenko V 

PROVIDER: S-EPMC12569754 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature