3. Signal recognition particle(SRP) pathway is a highly conserved pathway for protein targeting, and was found sequentially in eukaryotes, prokaryotes and archaebacteria.

• 讯息（指挥）序列--蛋白质末端的一段疏水性氨基酸，在细菌中引导蛋白质分泌或在真核细胞中将蛋白质并入内质网。收藏指正