Envelope protein which is a major component of the mature virion (MV) membrane. Essential for membrane biogenesis. Is required, together with A17, to form bona fide crescents, which can progress to form the immature virion (IV) membrane. A14 and A17 form a lattice that is stabilized by disulfide bonds and serves as an anchor within the viral membrane to which several other proteins important in virion structure and morphogenesis attach. Homodimer; disulfide-linked. Interacts with A17. Component of the mature virion (MV) membrane. Phosphorylated by viral F10 kinase, phosphorylation state is regulated by H1 phosphatase. Belongs to the chordopoxvirinae A14 family.