Replicase of L-A virus-like particles of Saccharomyces cerevisiae. In vitro conversion of exogenous L-A and M1 single-stranded RNAs to double-stranded form.

摘要: Virus-like particles that contain L-A double-stranded RNA are known to have transcriptase activity whose product is single-stranded plus RNA. In low salt conditions, these release their and can then use added or M1 RNAs as templates synthesize respective RNAs. The reaction requires dialyzed virus-like the source of enzyme, a partially purified cell extract (host factor(s)), template, polyethylene glycol 6000, along with four NTPs. Crude host factor extracts prepared from mak3 mak10ta mutants also support effectively wild type strain, while crude pet18 mutant grown under nonpermissive conditions less effective. Template specificity in vitro same expected for enzyme vivo. Plus RNAs, but not 18 S rRNA, converted net synthesis. newly synthesized strand full-length minus strand. This demonstration replicase mature which consistent our previous replication model; difference between RNA-synthesizing (expected be intermediates vivo) just former RNA, latter