The type-2 peroxisomal targeting signal (PTS2) is one of two peptide motifs destining soluble proteins for peroxisomes. This signal acts as amphiphilic α-helix exposing the side chains of all conserved residues to the same side. PTS2 motifs are recognized by a bipartite protein complex consisting of the receptor PEX7 and a co-receptor. Cargo-loaded receptor complexes are translocated across the peroxisomal membrane by a transient pore and inside peroxisomes, cargo proteins are released and processed in many, but not all species. The components of the bipartite receptor are re-exported into the cytosol by a ubiquitin-mediated and ATP-driven export mechanism. Structurally, PTS2 motifs resemble other N-terminal targeting signals, whereas the functional relation to the second peroxisomal targeting signal (PTS1) is unclear. Although only a few PTS2-carrying proteins are known in humans, subjects lacking a functional import mechanism for these proteins suffer from the severe inherited disease rhizomelic chondrodysplasia punctata.

中文翻译：

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2型过氧化物酶体靶向信号。

2型过氧化物酶体靶向信号（PTS2）是两个肽基序之一，这些肽基序是过氧化物酶体的可溶性蛋白。该信号充当两亲性α-螺旋，将所有保守残基的侧链暴露在同一侧。PTS2基序可被由受体PEX7和共受体组成的二聚体蛋白复合物识别。载有货物的受体复合物通过一个短暂的孔和过氧化物酶体内部穿过过氧化物酶体膜转运，货物蛋白在许多但不是全部物种中被释放和加工。二聚体受体的成分通过泛素介导和ATP驱动的输出机制重新输出到细胞质中。在结构上，PTS2基序与其他N端靶向信号相似，而与第二个过氧化物酶体靶向信号（PTS1）的功能关系尚不清楚。