Crystal Structure of a Conserved Hypothetical Protein MJ0927 from Methanocaldococcus jannaschii Reveals a Novel Quaternary Assembly in the Nif3 Family

Figure 3

Sequence alignment of MJ0927with Methanotorris igneus METIG1297, Methanococcus maripaludis MMAR0896, and Thermus thermophilus HB8TTHA1606. The following NCBI gi accession numbers reference the sequences used for the alignment: MJ0927, 499172854; METIG1297, 503565355; MMAR0896, 501148655; TTHA1606, 499487006. Sequences are numbered according to MJ0927, and secondary structure elements are displayed above the alignment. Red asterisks indicate metal-binding residues. Blue triangles indicate residues predicted for DNA binding. Green circles indicate residues involved in hexamer formation. Residues that are completely conserved are highlighted in solid red boxes. Those with similarity of >70% are labeled in red. The alignment was generated with the ClustalW2 program [17] (http://www.ebi.ac.uk/Tools/msa/clustalw2/) and used as the input for the ESPript program [18], version 2.2 (http://espript.ibcp.fr/ESPript/cgi-bin/ESPript.cgi).