5.B.13.   The One Electron Transmembrane Transfer Complex (HmcABCDEF) Family 

This family of electron carrier systems has been implicated in transfer of single electrons from periplasmic H2 oxidation to sulfate reduction in the cytoplasm of Desulfovibrio species (Pires et al. 2006).

This family belongs to the Iron-Sulfur Protein (ISP) Superfamily.



Dörries, M., L. Wöhlbrand, M. Kube, R. Reinhardt, and R. Rabus. (2016). Genome and catabolic subproteomes of the marine, nutritionally versatile, sulfate-reducing bacterium Desulfococcus multivorans DSM 2059. BMC Genomics 17: 918.

Pires, R.H., S.S. Venceslau, F. Morais, M. Teixeira, A.V. Xavier, and I.A. Pereira. (2006). Characterization of the Desulfovibrio desulfuricans ATCC 27774 DsrMKJOP complex--a membrane-bound redox complex involved in the sulfate respiratory pathway. Biochemistry 45: 249-262.


TC#NameOrganismal TypeExample

The transmembrane electron carrier system, HmcABCDEF (Pires et al. 2006). Probably transfers electrons from the periplasm to the cytoplasm; involved in H2 oxidation (periplasm) and sulfate reduction (cytoplasm). HmcA of 545 aas and 1 TMS; similar to proteins in TC#s 9.B.11 and 9.B.5. HmcB of 370 aas and 2 TMSs; similar to proteins in TC#s 5.A.3 and 5.B.12.  HmcC of 388 aas; similar to proteins in TC# 5.A.3.  HmcD of 47 aas and 1 TMS. TmcE of 226 aas and 5 or 6 TMSs; similar to proteins in TC#s 5.B.11 and 3.D.7, and possibly to proteins in 5.B.3.  TmcF of 461 aas and 0 TMSs; similar to proteins in TC#s 5.B.11, 5.B.12 and 3.D.7.

HmcABCDEF of Desulfovibrio vulgaris


The HmcABCDEF transmembrane electron flow complex (Dörries et al. 2016).

HmcABCDEF of Desulfococcus multivorans
HmcA, AOY57585, 543 aas and 1 TMS
HmcB, AOY57586. 318 aas and 1 - 3 TMSs
HmcC, AOY57587, 409 aas and 10 TMSs
HmcD, AOY57588, 43 aas and 1 TMS
HmcE, AOY57589, 229 aas and 5 TMSs
HmcF, AOY57590, 464 aas, a cytoplasdmic iron-sulfur protein