Figure 2

ARHD gene libraries. (A) Relative frequency of ARHD gene types recovered in the gene libraries generated with the Ac114F/Ac596R primer set [20]. Gene types were determined by RFLP analysis with the restriction endonuclease HaeIII, and sequencing. (B) Deduced amino acid sequences of the Rieske-type [2Fe-2S] cluster binding site from sediment clones and reference bacteria. Only one clone for each ARHD type found in the libraries is shown, selected as being the sequence most frequently found in the libraries. PhnAc, A. faecalis AFK2 dioxygenase large subunit (accession number BAA76323); NahAc, P. putida NCIB 9816-4 naphthalene 1,2-dioxygenase large subunit [AAO64274]. The numbering on the top indicates the deduced amino acid residues of NahAc from P. putida NCIB9816-4. Arrows indicate the position of Cys and His residues involved in the coordination of the Rieske [2Fe-2S] center. The last two lines indicate consensus sequences for the shown alignment and for all ARHD sequences found in the libraries, respectively.