The SecA ATPase is involved in the insertion and retraction of preproteins through the plasma membrane. This domain has been found to cross-link to preproteins, thought to indicate a role in preprotein binding. The pre-protein cross-linking domain is comprised of two sub domains that are inserted within the ATPase domain [1].

1: Nucleotide control of interdomain interactions in the conformational reaction cycle of SecA. Hunt JF, Weinkauf S, Henry L, Fak JJ, McNicholas P, Oliver DB, Deisenhofer J; Science 2002;297:2018-2026. PMID:12242434