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3.A.1.152.1
LPS export system, LptF (M), LptG (M) and LptB (C).  This system is also listed in TCDB under TC#1.B.42.1.2 as part of a multicomponent system.  The entire system is described in detail there. LptB2FG extracts LPSs from the IM and transports them to the outer membrane. Luo et al. 2017 reported the crystal structure of nucleotide-free LptB2FG from P. aeruginosa. It shows that LPS transport proteins LptF and LptG each contain a TM domain (TMD), a periplasmic beta-jellyroll-like domain and a coupling helix that interacts with LptB on the cytoplasmic side. The LptF and LptG TMDs form a large outward-facing V-shaped cavity in the IM. Mutational analyses suggested that LPS may enter the central cavity laterally, via the interface of the TMD domains of LptF and LptG, and is expelled into the beta-jellyroll-like domains upon ATP binding and hydrolysis by LptB. These studies suggest a mechanism for LPS extraction by LptB2FG that is distinct from those of classical ABC transporters that transport substrates across the IM (Luo et al. 2017). LptB2FG extracts LPS from the periplasmic face of the IM through a pair of lateral gates and then powers transperiplasmic transport to the OM through a slide formed by either of the periplasmic domains of LptF or LptG, LptC, LptA and the N-terminal domain of LptD. The structural and functional studies of the seven lipopolysaccharide transport proteins provide a platform to explore the unusual mechanisms of LPS extraction, transport and insertion from the inner membrane to the outer membrane (Dong et al. 2017). LptB2 binds novobiocin which stimulates its export activity and renders the membrane more impermeable to novobiocin (Luo et al. 2017 reported the crystal structure of nucleotide-free LptB2FG from P. aeruginosa. It shows that LPS transport proteins LptF and LptG each contain a TM domain (TMD), a periplasmic beta-jellyroll-like domain and a coupling helix that interacts with LptB on the cytoplasmic side. The LptF and LptG TMDs form a large outward-facing V-shaped cavity in the IM. Mutational analyses suggested that LPS may enter the central cavity laterally, via the interface of the TMD domains of LptF and LptG, and is expelled into the beta-jellyroll-like domains upon ATP binding and hydrolysis by LptB. These studies suggest a mechanism for LPS extraction by LptB2FG that is distinct from those of classical ABC transporters that transport substrates across the IM (Luo et al. 2017). LptB2FG extracts LPS from the periplasmic face of the IM through a pair of lateral gates and then powers transperiplasmic transport to the OM through a slide formed by either of the periplasmic domains of LptF or LptG, LptC, LptA and the N-terminal domain of LptD. The structural and functional studies of the seven lipopolysaccharide transport proteins provide a platform to explore the unusual mechanisms of LPS extraction, transport and insertion from the inner membrane to the outer membrane (Dong et al. 2017). LptB2 binds novobiocin which stimulates its export activity and renders the membrane more impermeable to novobiocin (Luo et al. 2017). LptB2FG extracts LPS from the periplasmic face of the IM through a pair of lateral gates and then powers transperiplasmic transport to the OM through a slide formed by either of the periplasmic domains of LptF or LptG, LptC, LptA and the N-terminal domain of LptD. The structural and functional studies of the seven lipopolysaccharide transport proteins provide a platform to explore the unusual mechanisms of LPS extraction, transport and insertion from the inner membrane to the outer membrane (Dong et al. 2017). LptB2 binds novobiocin which stimulates its export activity and renders the membrane more impermeable to novobiocin (May et al. 2017).

Accession Number:Q9HVV6
Protein Name:Probable ATP-binding component of ABC transporter
Length:241
Molecular Weight:26450.00
Species:Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1) [208964]
Number of TMSs:1
Substrate lipopolysaccharide

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FASTA formatted sequence
1:	MATLKAQHLA KSYKGRQVVR DVSMSIDSGQ IVGLLGPNGA GKTTCFYMIV GLVQADQGVV 
61:	RIDEQNVTHL PMHGRARAGI GYLPQEASIF RKLSVSDNIM AILETRSDLD RNGRKEALEG 
121:	LLQEFHIHHI RDNLGMSLSG GERRRVEIAR ALASAPKFIL LDEPFAGVDP ISVGDIKQII 
181:	HHLKAKGIGI LITDHNVRET LDICETAYIV NDGQLIAEGD AESILANDLV KEVYLGHEFR 
241:	L