Helicase transcriptional silencer protein. Molecular model of the helicase protein MOM1 acting as a transcriptional silencer. Helicases are enzymes that carry out several roles, primarily separating the two strands of the DNA (deoxyribonucleic acid) double helix, by breaking the hydrogen bonds between nucleotide bases. This helicase enzyme is from the plant Arabidopsis thaliana. It has four protein chains (red, orange, blue, green).