TCDB is operated by the Saier Lab Bioinformatics Group
« See all members of the family


3.A.1.106.18
Peptide and multidrug resistance porter of the ABC superfamily, TmrAB. TmrA (Q72J05; 600 aas with 6 N-terminal TMSs) and TmrB (Q72J04; 578 aas with 6 N-terminal TMSs) comprise this heterodimeric transporter, both proteins of the M-C structure.  The system has been found to export the dye, hoechst 33342, and to be inhibited by verapamil (Zutz et al. 2011). The subnanometre-resolution structure of detergent-solubilized TmrAB in a nucleotide-free, inward-facing conformation by single-particle electron cryomicroscopy has been solved (Kim et al. 2015). A cavity in the transmembrane domain is accessible laterally from the cytoplasmic side of the membrane as well as from the cytoplasm, indicating that the transporter lies in an inward-facing open conformation. The two nucleotide-binding domains remain in contact via their carboxy-terminal helices. Comparison between this structure and those of other ABC transporters suggests a possible trajectory of conformational changes that involves a sliding and rotating motion between the two nucleotide-binding domains during the transition from the inward-facing to outward-facing conformations (Kim et al. 2015). A subset of annular lipids is normally invariant in composition, with negatively charged lipids binding tightly to TmrAB, suggesting that this exporter may be involved in glycolipid translocation (Bechara et al. 2015). Coupled ATPase-adenylate kinase activity in ABC transporters including TmrAB has been demonstrated (Kaur et al. 2016). A 2.7-Å X-ray structure of TmrAB has been determined. It not only shares structural homology with the antigen translocation complex TAP, but is also able to restore antigen processing in human TAP-deficient cells. TmrAB exhibits a broad peptide specificity and can concentrate substrates several thousandfold, using only one single active ATP-binding site. It adopts an asymmetric inward-facing state, and the C-terminal helices, arranged in a zipper-like fashion, play a role in guiding the conformational changes associated with substrate transport (Nöll et al. 2017). Conformational coupling and trans-inhibition have been characterized (Barth et al. 2018).

Accession Number:Q72J05
Protein Name:Multidrug resistance ABC transporter ATP-binding and permease protein
Length:600
Molecular Weight:67880.00
Species:Thermus thermophilus (strain HB27 / ATCC BAA-163 / DSM 7039) [262724]
Number of TMSs:6
Substrate

Cross database links:

Structure:
5MKK   6RAF   6RAG   6RAH   6RAI   6RAJ   6RAK   6RAL   6RAM   6RAN   [...more]

External Searches:

  • Search: DB with
  • BLAST ExPASy (Swiss Institute of Bioinformatics (SIB) BLAST)
  • CDD Search (Conserved Domain Database)
  • Search COGs (Clusters of Orthologous Groups of proteins)
  • 2° Structure (Network Protein Sequence Analysis)

Analyze:

Predict TMSs (Predict number of transmembrane segments)
Window Size: Angle:  
Window Size: Angle:  
FASTA formatted sequence
1:	MTEDTYSKAF DRALFARILR YVWPYRLQVV LALLFLLVVT LAAAATPLFF KWAIDLALVP 
61:	TEPRPLAERF HLLLWISLGF LAVRAVHFAA TYGETYLIQW VGQRVLFDLR SDLFAKLMRL 
121:	HPGFYDRNPV GRLMTRVTSD VDAINQFITG GLVGVIADLF TLVGLLGFML FLSPKLTLVV 
181:	LLVAPVLLAV TTWVRLGMRS AYREMRLRLA RVNAALQENL SGVETIQLFV KEREREEKFD 
241:	RLNRDLFRAW VEIIRWFALF FPVVGFLGDF AVASLVYYGG GEVVRGAVSL GLLVAFVDYT 
301:	RQLFQPLQDL SDKFNLFQGA MASAERIFGV LDTEEELKDP EDPTPIRGFR GEVEFRDVWL 
361:	AYTPKGVEPT EKDWVLKGVS FRVRPGEKVA LVGATGAGKT SVVSLIARFY DPQRGCVFLD 
421:	GVDVRRYRQE ELRRHVGIVL QEPFLFSGTV LDNLRLFDPS VPPERVEEVA RFLGAHEFIL 
481:	RLPKGYQTVL GERGAGLSTG EKQLLALVRA LLASPDILLI LDEATASVDS ETEKRLQEAL 
541:	YKAMEGRTSL IIAHRLSTIR HVDRILVFRK GRLVEEGSHE ELLAKGGYYA ALYRLQFQEA