Cloning of the Haemophilus influenzae Dam methyltransferase and analysis of its relationship to the Dam methyltransferase encoded by the HP1 phage.
In this paper we report cloning and experimental characterization of the DNA adenine methyltransferase (dam) gene from Haemophilus influenzae and comparison of its product with the Dam protein from the lysogenic phage of H. influenzae, HP1. Molecular modeling of M.HinDam and M.HP1Dam was carried out, providing a framework for a comparative analysis of these enzymes and their close homologs in the structural context. Both proteins share the common fold and essential cofactor-binding and catalytic residues despite overall divergence. However, subtle but significant differences in the cofactor-binding pocket have been identified. Moreover, while M.HinDam seems to contact its target DNA sequence using a number of loops, most of them are missing from M.HP1Dam. Analysis of both MTases suggests that their catalytic activity was derived from a common ancestor, but similar sequence specificities arose by convergence.
Bujnicki
J M
JM
Bioinformatics Laboratory, International Institute of Molecular and Cell Biology, Warszawa, Poland. iamb@bioinfo.pl
Radlinska
M
M
Zaleski
P
P
Piekarowicz
A
A
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001435:Bacteriophages / Q000378:metabolism*; D002384:Catalysis; D020134:Catalytic Domain; D003001:Cloning, Molecular; D004791:Enzyme Inhibitors / Q000737:chemistry; D006193:Haemophilus influenzae / Q000201:enzymology* / Q000235:genetics*; D008745:Methylation; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics*
D004791:Enzyme Inhibitors; C058693:Dam methyltransferase; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)