Figure 6.
Analysis of the subunit structure of SSB assessed by glutaraldehyde chemical cross-linking in the presence and absence of ssDNA (1 µM 18mer oligonucleotide). The presence of DNA gives rise to a significant increase in the proportion of cross-linked species evident after SDS–PAGE (lane 5). Retarded species have mobilities consistent with the formation of cross-linked dimers and tetramers of SSB. No further-retarded complexes were observed. Lane 1, markers; lane 2, 5 µM recombinant SSB, no glutaraldehyde; lane 3, 5 µM SSB without DNA; lane 4, 1 µM SSB without DNA; lane 5, 5 µM SSB with DNA; lane 6, 1 µM SSB with DNA.