SRP19 is a critical component of the signal recognition particle (SRP), a ribonucleoprotein complex that mediates cotranslational targeting of secretory and membrane proteins to the endoplasmic reticulum 1. The protein directly binds to 7SL RNA and plays an essential scaffolding role in SRP assembly by bridging the tips of RNA helices 6 and 8, creating a stable network of protein-RNA interactions 2. SRP19 binding precedes and promotes the association of SRP54, the main signal sequence recognition component, demonstrating its fundamental role in SRP assembly 2. Structurally, SRP19 exhibits anti-cooperative binding with the SRP68/72 heterodimer, suggesting complex regulatory mechanisms in SRP formation 3. The protein is highly conserved across species, with functional complementation observed between plant and mammalian components 4. Disease relevance includes severe congenital neutropenia caused by SRP19 genetic defects, which disrupt neutrophil differentiation through altered protein processing and ER homeostasis 1. Additionally, SRP19 represents a therapeutic vulnerability in colorectal cancers with APC deletions, where SRP19 is frequently co-deleted, leading to reduced protein secretion capacity and increased ER stress susceptibility 5. The essential nature of SRP19 is demonstrated by its requirement for cell viability in multiple organisms 6.