Protein Family Models

In most members this domain covers almost the whole sequence, but a few member-sequences also carry a TonB_C domain, PF03544. This domain has a lipocalin fold. (from Pfam)

Date:

2024-08-14

The TonB_C domain is the well-characterised C-terminal region of the TonB receptor molecule. This protein is bound to an inner membrane-bound protein ExbB via a globular domain and has a flexible middle region that is likely to help in positioning the C-terminal domain into the iron-transporter barrel in the outer membrane [1]. TonB_C interacts with the N-terminal TonB box of the outer membrane transporter that binds the Fe3+-siderophore complex. The barrel of the transporter, consisting of 22 beta-sheets and an inside plug, binds the iron complex in the barrel entrance [2]. [1]. 16741124. Outer membrane active transport: structure of the BtuB:TonB complex. Shultis DD, Purdy MD, Banchs CN, Wiener MC;. Science. 2006;312:1396-1399. [2]. 21277822. Recent insights into iron import by bacteria. Braun V, Hantke K;. Curr Opin Chem Biol. 2011;15:328-334. (from Pfam)

Date:

2024-10-16

This HMM represents the C-terminal of TonB and is homologs. TonB is an energy-transducer for TonB-dependent receptors of Gram-negative bacteria. Most members are designated as TonB or TonB-related proteins, but a few represent the paralogous TolA protein. Several bacteria have up to four TonB paralogs. In nearly every case, a proline-rich repetive region is found N-terminal to this domain; these low-complexity regions are highly divergent and cannot readily be aligned. The region is suggested to help span the periplasm.

Date:

2021-05-12

energy transducer TonB interacts with outer membrane receptor proteins that carry out high-affinity binding and energy dependent uptake into the periplasmic space of specific substrates such as cobalamin, and various iron compounds (such as iron dicitrate, enterochelin, aerobactin, etc.)| M56 family metallopeptidase is an integral membrane metallopeptidase, containing a zinc-binding HEXXH motif; it allows bacteria to respond to presence of beta-lactam antibiotics by expression of beta-lactamases and penicillin-binding proteins; includes transmembrane proteins BlaR1 and MecR1; may also contain type IVB secretion system protein DotG/IcmE at the C-terminal end

Date:

2017-03-02