The DNA of a monkey papillomavirus (CgPV-1), originally isolated from a penile lesion on a Colobus monkey was cloned into the EcoRI site of the pUC18 vector and characterized. Using a variety of restriction enzymes a physical map of the DNA was constructed. Cross-hybridization with a variety of animal and human papillomaviruses under high (Tm-22 degrees C) and low (Tm-40 degrees C) stringency conditions indicated various degrees of homology. CgPV-1 showed higher homology with HPVs than it did with any other animal papillomaviruses tested. DNA similarities with the human papillomaviruses HPV-16 and HPV-18 that are frequently associated with cervical cancer, were manifested by extensive cross-hybridization under stringent conditions. Functional alignment of the genomic map of CgPV-1 with that of HPV-16 was carried out by determination of homology between specific restriction fragments of the two viral genomes in cross-hybridization analyses. This alignment was refined by sequencing two regions of approximately 200 bp of the CgPV-1 DNA, and aligning them by computer with their homologous HPV-16 counterparts. CgPV-1 DNA in its pUC18 vector, transformed NIH 3T3 cells with roughly the same efficiency as BPV-1, as determined by the number of transformed foci generated per ug of DNA. The data presented indicate that the state of the CgPV-1 viral DNA in these transformed cells is integrated and partially deleted, not unlike the genomes of HPV-16 and HPV-18 characterized in cell lines derived from cervical cancers.