A protein complex capable of alkanesulfonate monooxygenase activity. Involved in the utilization of alkanesulfonates as sulfur sources under conditions of sulfate or cysteine starvation, catalyzing the conversion of alkanesulfonates into aldehydes and sulfite. In E.coli the complex consists of a SsuD tetramer. [ http://www.ncbi.nlm.nih.gov/pubmed/16997955 http://www.ncbi.nlm.nih.gov/pubmed/10480865 ]