TECHNICAL DESCRIPTION

The inventors have performed the complete identification of a novel member of the MCM2-8 family represented by the members MCM2-7 and MCM8, the MCM9 protein. Like MCM8, MCM9 is only present in the genome of higher eukaryotes. This protein contains an MCM8-like ATP binding and -hydrolysis motif implicated in helicase activity. Strikingly, in addition, MCM9 contains a unique carboxy-terminal domain which has only weak homology to MCM2-7 and MCM8, but stretches of amino acids, ranging from4 to 10 amino acids, are highly conserved within MCM9 homologs. The inventors have also shown that the very recently reported human MCM9 protein, which resembles a truncated MCM-like protein missing a part of the MCM2-7 domain, is an incomplete form of the full length human MCM9 protein. Searching the human genome with either the newly identified human MCM9 or other MCM protein sequences, the inventors have not detected further additional members of this DNA helicase family and suggest that it is constituted of eight members, falling into two different groups, one constituted by the MCM2-7 complex and the other by MCM8 and MCM9, which are present only in higher eukaryotes.