has role protective antigen role protective antigen Shigella protein Spa32 Oliver He protein Allen Xiang S. flexneri M90T is a colonisation-defective mutant with a transposon in fnr, which encodes a regulator of anaerobic metabolism. To establish whether FNR-mediated repression of spa32 and spa33 contributes to increased Shigella entry into cells in an anaerobic cabinet, recombinant M90T strains were constructed which contain spa32 and spa33 under the control of either their native promoters (M90Tp32/33) or promoters with disrupted FNR boxes (M90Tp#32/#33).The presence in M90T of spa32 and spa33 alleles that are not repressed by FNR led to IpaB secretion during anaerobic growth, and loss of the increased entry of Shigella into cells in an anaerobic cabinet [PubMed: 20436458]. Protegen ID: 288; NCBI Gene GI: 876502; NCBI Protein GI: 13449098; NCBI Protein Accession: NP_085314; NCBITaxon: 424718