TY - JOUR AV - public ID - heidok8581 SP - 977 VL - 121 EP - 985 UR - https://archiv.ub.uni-heidelberg.de/volltextserver/8581/ N2 - Signal recognition particle (SRP), the cytoplasmic ribonucleoprotein particle that mediates the targeting of proteins to the ER, consists of a 7S RNA and six different proteins. The 68- (SRP68) and 72-(SRP72) kD proteins of SRP are bound to the 7S RNA of SRP as a heterodimeric complex (SRP68/72). Here we describe the primary structure of SRP72 and the assembly of SRP68, SRP72 and 7S RNA into a ribonucleoprotein particle. The amino acid sequence deduced from the cDNA of SRP72 reveals a basic protein of 671 amino acids which shares no sequence similarity with any protein in the sequence data libraries. Assembly of SRP72 into a ribonucleoprotein particle required the presence of 7S RNA and SRP68. In contrast, SRP68 alone specifically bound to 7S RNA. SRP68 contacts the 7S RNA via its NH2-terminal half while COOH-terminal portions of SRP68 and SRP72 are in contact with each other in SRP. SRP68 thus serves as a link between 7S RNA and SRP72. As a large NH2-terminal domain of SRP72 is exposed on SRP it may be a site of contact to other molecules involved in the SRP cycle between the ribosome and the ER membrane. A1 - Lütcke, Henrich A1 - Prehn, Siegfried A1 - Ashford, Anthony J. A1 - Remus, Michael A1 - Frank, Rainer A1 - Dobberstein, Bernhard IS - 5 Y1 - 1993/// TI - Assembly of the 68- and 72-kD Proteins of Signal Recognition Particle with 7S RNA JF - The Journal of Cell Biology ER -