Lipoprotein LptE is required for the assembly of LptD by the beta-barrel assembly machine in the outer membrane of Escherichia coli.
Most Gram-negative bacteria contain lipopolysaccharide (LPS), a glucosamine-based phospholipid, in the outer leaflet of the outer membrane (OM). LPS is unique to the bacterial OM and, in most cases, essential for cell viability. Transport of LPS from its site of synthesis to the cell surface requires eight essential proteins, MsbA and LptABCDEFG. Although the key players have been identified, the mechanism of LPS transport and assembly is not clear. The stable LptD/E complex is present at the OM and functions in the final stages of LPS assembly. Here, we have identified the mutant allele lptE6, which causes a two-amino-acid deletion in the lipoprotein LptE that affects its interaction with LptD. Highly specific suppressor mutations were isolated not only in lptD but also in bamA, which encodes the central component of the β-barrel assembly machine. We show that lptE6 and both suppressor mutations affect the assembly of the LptD/E complex and suggest that the lipoprotein LptE interacts with LptD while this protein is being assembled by the β-barrel assembly machine.
Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
Gitanjali
G
Chimalakonda
Natividad
N
Ruiz
Shu-Sin
SS
Chng
Ronald A
RA
Garner
Daniel
D
Kahne
Thomas J
TJ
Silhavy
D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins; D001692:Biological Transport / Q000502:physiology; D002462:Cell Membrane / Q000235:genetics / Q000473:pathology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000235:genetics / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion
D018528:ATP-Binding Cassette Transporters; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008070:Lipopolysaccharides; C475958:LptD protein, E coli; C514179:LptE protein, E coli; C079726:MsbA protein, Bacteria; D046912:Multiprotein Complexes
Proc Natl Acad Sci U S A. 2006 Aug 1;103(31):11754-9
16861298
Mol Microbiol. 2006 Jul;61(1):151-64
16824102
Genes Dev. 1989 Sep;3(9):1462-71
2691330
Biochemistry. 1976 Jun 15;15(12):2561-70
820368
Nat Rev Microbiol. 2006 Jan;4(1):57-66
16357861
Proc Natl Acad Sci U S A. 2000 Jun 6;97(12):6640-5
10829079
J Mol Biol. 1988 Jul 5;202(1):45-58
3050121
Science. 2007 Aug 17;317(5840):961-4
17702946
Proc Natl Acad Sci U S A. 2001 Jun 5;98(12):6742-6
11381128
Science. 2001 Oct 12;294(5541):361-4
11520949
Proc Natl Acad Sci U S A. 2008 Apr 8;105(14):5537-42
18375759
Microbiol Rev. 1989 Mar;53(1):1-24
2540407
Proc Natl Acad Sci U S A. 2005 Dec 6;102(49):17775-9
16303867
Proteomics. 2009 May;9(9):2432-43
19343722
Nat Rev Microbiol. 2009 Sep;7(9):677-83
19633680
J Biol Chem. 2005 Feb 11;280(6):4504-9
15576375
Proc Natl Acad Sci U S A. 2011 Feb 8;108(6):2486-91
21257904
Biosci Biotechnol Biochem. 2009 Mar 23;73(3):465-73
19270402
J Biol Chem. 2002 Sep 27;277(39):36697-705
12119303
J Bacteriol. 2007 Jan;189(1):244-53
17056748
J Biol Chem. 1972 Jun 25;247(12):3973-86
4624447
Trends Biochem Sci. 2003 Oct;28(10):523-6
14559180
J Biol Chem. 2004 Oct 22;279(43):45102-9
15304478
Proc Natl Acad Sci U S A. 2010 Jul 6;107(27):12245-50
20566849
J Bacteriol. 2008 Jul;190(13):4460-9
18424520
J Bacteriol. 1987 Dec;169(12):5692-9
3316191
Cell. 2005 Apr 22;121(2):235-45
15851030
J Biol Chem. 2008 Jul 18;283(29):20342-9
18480051
Microbiol Mol Biol Rev. 2003 Dec;67(4):593-656
14665678
Proc Natl Acad Sci U S A. 2004 Jun 22;101(25):9417-22
15192148
Genes Dev. 1993 Dec;7(12B):2618-28
8276244
Annu Rev Biochem. 2002;71:635-700
12045108
J Biol Chem. 2001 Apr 13;276(15):11461-4
11278265
Mol Microbiol. 2005 Mar;55(5):1403-12
15720549
Proc Natl Acad Sci U S A. 2010 Mar 23;107(12):5363-8
20203010
FEBS Lett. 2009 Jul 7;583(13):2160-4
19500581
Cell. 2005 Apr 22;121(2):307-17
15851036
Biochemistry. 2010 Jun 8;49(22):4565-7
20446753
Annu Rev Microbiol. 2007;61:191-214
17506684
Mol Microbiol. 2002 Sep;45(5):1289-302
12207697
ACS Chem Biol. 2006 Jul 21;1(6):385-95
17163776
J Biol Chem. 2001 Jun 15;276(24):20866-75
11274153
Genetics. 1989 Jul;122(3):491-501
2547691
J Bacteriol. 1995 Jul;177(14):4121-30
7608087
Proc Natl Acad Sci U S A. 2007 Apr 10;104(15):6400-5
17404237