TABLE 2.

MCM mutant phenotypes

ExptGeneResult for wild typeGrowth of mutant
Walker AcWalker BArg finger
GeneticMCM2+±
    complementationaMCM3+
MCM4++
MCM5+
MCM6++
MCM7+
OverexpressionMCM2++++
    lethalitybMCM3±+++
MCM4+++
MCM5+±+
MCM6+++
MCM7+++++++++
  • a Complementation experiments express the indicated MCM genes under the control of the MCM5 promoter on an ARS/CEN plasmid over a deletion of the corresponding gene. MCM2 alleles were untagged; the other genes contained a C-terminal HA/His10 epitope tag. +, growth; −, no growth; ±, weak growth.

  • b Overexpression lethality experiments were performed using integrated constructs under the control of the GAL1-10 promoter. MCM2 alleles were untagged, while the other alleles contained a C-terminal epitope tag: MCM3 alleles contained a 3× HA tag, MCM4 alleles contained either a 3× HA or 3× Myc tag, while the MCM5, -6, and -7 alleles contained a single FLAG tag. Western blot analysis was preformed to verify galactose-induced expression of full-length protein. Symbols indicate growth on galactose-containing medium: +++, no growth (i.e., complete lethality); +, poor growth; ± good growth; −, normal growth (i.e., no inhibition by galactose).

  • c The phenotypes of the Walker A alleles are reprinted from our prior publication (29) and are included for purposes of comparison.