ANALYSIS OF THE NUCLEIC-ACID ANNEALING ACTIVITIES OF NUCLEOCAPSID PROTEIN FROM HIV-1

Retroviral nucleocapsid (NC) protein is an integral part of the virion nucleocapsid where it is in tight association with genomic RNA and th e tRNA primer, NC protein is necessary for the dimerization and encaps idation of genomic RNA, the annealing of the tRNA primer to the primer binding site (PBS) and the initial strand transfer event, Due to the general nature of NC protein-promoted annealing, its use to improve nu cleic acid interactions in various reactions can be envisioned, Parame ters affecting NC-promoted nucleic acid annealing of NCp7 from HIV-1 h ave been analyzed, The promotion of RNA:RNA and RNA:DNA annealing by N Cp7 is more sensitive to the concentration of MgCl2 than the promotion of DNA:DNA hybridization, Stimulation of complex formation for all th ree complexes was efficient at 0-90 mM NaCl, between 23 and 55 degrees C and at pH values between 6.5 and 9.5, inclusive, Parameters affecti ng NCP7-promoted hybridization of tRNA(Lys,3) to the PBS, which appear s to be specific for NC protein, will be discussed, Results implicate the basic regions of NCp7, but not the zinc fingers, in promoting the annealing of complementary nucleic acid sequences, Finally, NCp7 stran d transfer activity aids the formation of the most stable nucleic acid complex.