Molecular chaperone required for SptP stabilization and secretion. The structure of the SptP-SicP complex contains four molecules of the chaperone SicP, aligned in a linear fashion and arranged in two sets of tightly bound homodimers that bind two SptP molecules. The SicP homodimers do not interact with each other, but are held together by a molecular interface formed between two SptP molecules. The chaperone-binding domain of SptP does not adopt a globular fold for interaction with SicP. Each SptP molecule is wrapped around by three SicP chaperones (two chaperones from one homodimer and a third one from the opposite homodimer pair). SptP interacts with SicP chaperone dimers mainly through four regions of its chaperone-binding domain. Belongs to the SicP family. Extended N-terminus.