3FTJ

Crystal structure of the periplasmic region of MacB from Actinobacillus actinomycetemcomitans

Summary for 3FTJ

• Entry DOI: 10.2210/pdb3ftj/pdb
• Descriptor: Macrolide export ATP-binding/permease protein macB (2 entities in total)
• Functional Keywords: macrolide-specific pump, abc-type transporter, heat stable exotoxin ii, membrane protein, periplasmic region, antibiotic resistance, atp-binding, cell inner membrane, cell membrane, hydrolase, membrane, nucleotide-binding, transmembrane, transport
• Biological source: Actinobacillus actinomycetemcomitans (Haemophilus actinomycetemcomitans)
• Cellular location: Cell inner membrane; Multi-pass membrane protein (Potential): Q2EHL8
• Total number of polymer chains: 1
• Total formula weight: 24726.88

Authors

Xu, Y.,Ha, N.C. (deposition date: 2009-01-13, release date: 2009-05-26, Last modification date: 2024-03-20)

Primary citation

Xu, Y.,Sim, S.-H.,Nam, K.H.,Jin, X.L.,Kim, H.-M.,Hwang, K.Y.,Lee, K.,Ha, N.-C.
Crystal structure of the periplasmic region of MacB, a noncanonic ABC transporter
Biochemistry, 48:5218-5225, 2009

PubMed Abstract: MacB is a noncanonic ABC-type transporter within Gram-negative bacteria, which is responsible both for the efflux of macrolide antibiotics and for the secretion of heat-stable enterotoxin II. In Escherichia coli, MacB requires the membrane fusion protein MacA and the multifunctional outer membrane channel TolC to pump substrates to the external medium. Sequence analysis of MacB suggested that MacB has a relatively large periplasmic region. To gain insight into how MacB assembles with MacA and TolC, we determined the crystal structure of the periplasmic region of Actinobacillus actinomycetemcomitans MacB. Fold matching program reveals that parts of the MacB periplasmic region have structural motifs in common with the RND-type transporter AcrB. Since it behaved as a monomer in solution, our finding is consistent with the dimeric nature of full-length MacB, providing an insight into the assembly in the tripartite efflux pump.

PubMed: 19432486
DOI: 10.1021/bi900415t

Experimental method

X-RAY DIFFRACTION (1.999 Å)