PDB ID or protein name

2cfq » Lactose permease LacY, structure 1

2cfq » Lactose permease LacY, structure 1
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Topology in Bacterial Gram-negative inner membrane
Topologyout side
in side
2cfq » Lactose permease LacY, structure 1
Hydrophobic Thickness 31.9 ± 1.1 Å
Tilt Angle 5 ± 1°
ΔGtransfer -87.9 kcal/mol
Links to 2cfq PDB Sum, PDB, SCOP, MSD, OCA, MMDB
Topology subunit A (N-terminus in)
Resolution 2.95 Å
Other PDB entries representing this structure none
Number of TM Secondary Structures 12
1 transmembrane subunit
A - Tilt: 4° - Segments: 1(11-34), 2(45-67), 3(75-96), 4(105-129), 5(143-164), 6(167-186), 7(220-247), 8(257-279), 9(288-308), 10(312-333), 11(349-370), 12(381-399)
Experimental Verification for 2cfq » Lactose permease LacY, structure 1
Results are consistent with chemical modification and spin-labeling studies of lactose permease (Voss et al. 1996, Frillingos et al. 1998, Zhao et al. 1999, Kwaw et al. 2001, Guan et al. 2002, Ermolova et al. 2003, Venkatesan et al. 2000a,b,c, Zhang et al. 2003). Average tilt angle of TM helices (20 degrees) is smaller than estimated by ATR FTIR (Le Coutre et al. 1997). Hydrophobic thickness is ~2 A smaller than was calculated for the lower resolution structure (1pv6).
11 references
Ermolova N, Guan L, and Kaback HR (2003) Intermolecular thiol cross-linking via loops in the lactose permease of Escherichia coli. Proc. Natl. Acad. Sci. U.S.A. 100: 10187-10192. PubMed
Frillingos S, Sahin-Toth M, Wu JH, Kaback HR (1998) Cys-scanning mutagenesis: a novel approach to structure-function relationships in polytopic membrane proteins. FASEB J. 12: 1281-1299. PubMed
Guan L, Murphy FD, and Kaback HR (2002) Surface-exposed positions in the transmembrane helices of the lactose permease of Escherichia coli determined by intermolecular thiol cross-linking. Proc. Natl. Acad. Sci. U.S.A. 99: 3475-3480. PubMed
Kwaw I, Zen KC, Hu YL, and Kaback HR (2001) Site-directed sulfhydryl labeling of the lactose permease of Escherichia coli: Helices IV and V that contain the major determinants for substrate binding. Biochemistry 40: 10491-10499. PubMed
Le Coutre J, Narasimhan LR, Patel CKN, and Kaback HR (1997) The lipid bilayer determines helical tilt angle and function in lactose permease of Escherichia coli. Proc. Nat. Acad. Sci. USA94: 10167-10171. PubMed
Venkatesan P, Hu YL, and Kaback HR (2000c) Site-directed sulfhydryl labeling of the lactose permease of Escherichia coli: Helix X. Biochemistry 39: 10656-10661. PubMed
Venkatesan P, Kwaw I, Hu YL, and Kaback HR (2000a) Site-directed sulfhydryl labeling of the lactose permease of Escherichia coli: Helix VII. Biochemistry 39: 10641-10648. PubMed
Venkatesan P, Liu ZL, Hu YL, and Kaback HR (2000b) Site-directed sulfhydryl labeling of the lactose permease of Escherichia coli: N-ethylmaleimide-sensitive face of helix II. Biochemistry 39: 10649-10655. PubMed
Voss J, He MM, Hubbell WL, and Kaback HR (1996) Site-directed spin labeling demonstrates that transmembrane domain XII in the lactose permease of Escherichia coli is an alpha-helix. Biochemistry 35: 12915-12918. PubMed
Zhang W, Hu YL, and Kaback HR (2003) Site-directed sulfhydryl labeling of helix IX in the lactose permease of Escherichia coli. Biochemistry 42 (17): 4904-4908. PubMed
Zhao M, Zen KC, Hernandez-Borrell J, Altenbach C, Hubbell WL, and Kaback HR (1999) Nitroxide scanning electron paramagnetic resonance of helices IV and V and the intervening loop in the lactose permease of Escherichia coli. Biochemistry 38: 15970-15977. PubMed