Overexpression in wild-type cells increases the number of cells with double magnetosome chains significantly. The 4 genes of this operon collectively influence magnetosome size and number. Part of the probable mms6 operon. Normal magnetic response, fewer, larger magnetosomes; cells accumulate 20% more iron (PubMed:24816605). Deletion of the 4 gene operon (mms6, mmsF, mms36 and mms48) gives an intermediate magnetic response with fewer, smaller magnetosomes in irregular pseudo-chains (PubMed:22043287, PubMed:24816605). This bacteria makes up to 60 cubo-octahedral magnetosomes of about 45 nm in diameter which contain membrane-bound crystals of magnetite (Fe(3)O(4)).