Figure 2.

Alignments of the N-terminal regions of RepA homologs from the Sulfolobus cryptic plasmids pRN1, pSSVx, pORA1, pIT3 and pTIK4 and the conjugative plasmids pKEF9 and pARN3. The double line above the alignment denotes the DNA-binding domain and the single line delineates the active site subdomain. Functionally important amino acids in the latter are indicated by asterisks, and the DXD/DXE motif is shown (Lipps 2003, Lipps et al. 2004). Amino acids involved in the zinc-binding stem are denoted by Z. The sequence of putative RepA homolog of pIT3 is from GenBank accession no. AY591755 (H.-P. Klenk, e-Gene Biotechnologie GmbH, Feldafing, Germany, unpublished data). Alignments of identical and similar amino acids are indicated by black and gray boxes, respectively, obtained with Boxshade (http://www.ch.embnet.org).