Abstract: The invention provides ssDNA-binding proteins from three species of archaeons, Methanococcus jannaschii, Methanobacter theromoautotrophicum, and Archaeoglobus fulgidus, as well as the ability to identify ssDNA-binding proteins from other archaeons. The proteins help render DNA more accessible to DNA polymerase and are robust reagents for a variety of biotechnical processes, including PCR. The invention further provides nucleic acids encoding such proteins, vectors for transfecting host cells, host cells comprising the vectors, and methods of using the proteins.