9.B.90 The Putative Channel Forming 2 TMSs MamC (MamC) Family

The MamC family consists of magnetosome-associated orthologues, some of which are designated 'tightly bound bacterial magnetic particle protein'. It may play a role in iron transport with the magnetosome (Scheffel et al., 2008). Homologues (120-130aas; 2TMSs) are found in a variety of Gram-negative α-proteobacteria, with and without magnetosomes. They show limited sequence similarity with portions of A+G-rich animal elastins (EAW69628).



Nudelman, H., T. Perez Gonzalez, S. Kolushiva, M. Widdrat, V. Reichel, A. Peigneux, G. Davidov, R. Bitton, D. Faivre, C. Jimenez-Lopez, and R. Zarivach. (2018). The importance of the helical structure of a MamC-derived magnetite-interacting peptide for its function in magnetite formation. Acta Crystallogr D Struct Biol 74: 10-20.

Scheffel, A., A. Gärdes, K. Grünberg, G. Wanner, and D. Schüler. (2008). The major magnetosome proteins MamGFDC are not essential for magnetite biomineralization in Magnetospirillum gryphiswaldense but regulate the size of magnetosome crystals. J. Bacteriol. 190: 377-386.


TC#NameOrganismal TypeExample
9.B.90.1.1Magnetosome protein, MamC (Scheffel et al., 2008).BacteriaMamC of Magnetospirillum gryphiswaldense (Q93DY1)

Tightly bound bacterial magnetic particle protein, Mms13 or MamC of 145 aas and 2 or 3 TMSs.  It is magnetosome-associated protein with 2 TMSs, connected by a 21-amino-acid peptide. In vitro studies showed that it forms a helical structure that can interact with the magnetite surface and affect the size and shape of the growing crystal (Nudelman et al. 2018).


Mms13 of Magnetospirillum magneticum


Uncharacterized protein with 122 aas and 3 TMSs in a 1 + 2 TMS arrangement.

UP of Thiocystis violascens (Chromatium violascens)


Uncharacterized protein of 125 aas and 3 TMSs in a 1 + 3 TMS arrangment.

UP of Arcobacter halophilus


Uncharacterized protein of 170 aas and 3 TMSs in a 1 + 2 TMS arrangement.

UP of Desulfovibrio brasiliensis


Uncharacterized protein of 121 aas and 3 TMSs.

UP of Rhodospirillum rubrum


Uncharacterized protein of 270 aas with 3 TMSs in a 1 + 2 TMS arrangement, with an N-terminal hydrophilic domain.  Not recognized by Pfam.

UP of Actinopolyspora alba