41. Open reading frame 2 ( ORF 2 ) codes a protein which possesses both endonuclease and reverse transcriptase activities. 42. E . coli cells contain two AP endonucleases : endonuclease IV ( endoIV ) and exonuclease III ( exoIII ). 43. The sequence altered by the mutation eliminates the recognition site for the restriction endonuclease MstII that recognizes the nucleotide sequence. 44. Heterogeneous nuclear ribonucleoprotein A1 has been shown to interact with BAT2, Flap structure-specific endonuclease 1 and I?B?. 45. Ronald W . Davis first discovered sticky ends as the product of the action of EcoRI, the restriction endonuclease . 46. EcoRV is the only type II restriction endonuclease known to cause a major protein-induced conformational change in the DNA. 47. The action of ligase I is stimulated by other LP-BER enzymes, particularly AP-endonuclease and DNA polymerase. 48. These include the four key proteins involved in DNA replication and FLAP endonuclease and the processing factor proliferating cell nuclear antigen. 49. A delay in the expression of the endonuclease relative to methylase is due to the inherent differences of the two proteins. 50. HEARO RNAs contain an open reading frame ( ORF ) that usually codes for a protein containing an HNH endonuclease domain.
