title: Specific interaction of proteins with 5 S RNA and tRNA in the 42 S storage particle of Xenopus oocytes.
abstract: During early oogenesis in amphibia, most of the 5 S RNA and tRNA is stored in a ribonucleoprotein particle that sediments at 42 S. In Xenopus laevis the 42 S particle contains two major proteins: of Mr 48 000 (P48) and 43 000 (P43). It is shown that heterogeneity in composition of the 42 S particle reflects a changing situation whereby initially, both 5 S RNA and tRNA are complexed with P48 (1 molecule 5 S RNA: 1 molecule P48; 2 or 3 molecules tRNA: 1 molecule P48), but later, tRNA becomes increasingly associated with P43 (in a 1:1 ratio) although 5 S RNA remains complexed with a cleavage product of P48. These changes relate to the eventual utilization of the excess 5 S RNA and tRNA in ribosome assembly and protein synthesis.
mesh_terms: D000818:Animals; D005260:Female; D046911:Macromolecular Substances; D008970:Molecular Weight; D009698:Nucleoproteins / Q000378:metabolism*; D009865:Oocytes / Q000502:physiology*; D010063:Ovum / Q000502:physiology*; D012335:RNA, Ribosomal / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000302:isolation & purification / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism*; D014981:Xenopus
chemical_list: D046911:Macromolecular Substances; D009698:Nucleoproteins; D012335:RNA, Ribosomal; D012261:Ribonucleoproteins; D012269:Ribosomal Proteins; D012343:RNA, Transfer