This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.


1fi1

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 1: Line 1:
-
[[Image:1fi1.gif|left|200px]]
+
{{Seed}}
 +
[[Image:1fi1.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1fi1| PDB=1fi1 | SCENE= }}
{{STRUCTURE_1fi1| PDB=1fi1 | SCENE= }}
-
'''FhuA in complex with lipopolysaccharide and rifamycin CGP4832'''
+
===FhuA in complex with lipopolysaccharide and rifamycin CGP4832===
-
==Overview==
+
<!--
-
BACKGROUND: FhuA, an integral membrane protein of Escherichia coli, actively transports ferrichrome and the structurally related antibiotic albomycin across the outer membrane. The transport is coupled to the proton motive force, which energizes FhuA through the inner-membrane protein TonB. FhuA also transports the semisynthetic rifamycin derivative CGP 4832, although the chemical structure of this antibiotic differs markedly from that of ferric hydroxamates. RESULTS: X-ray crystallography revealed that rifamycin CGP 4832 occupies the same ligand binding site as ferrichrome and albomycin, thus demonstrating a surprising lack of selectivity. However, the binding of rifamycin CGP 4832 is deviant from the complexes of FhuA with hydroxamate-type ligands in that it does not result in the unwinding of the switch helix but only in its destabilization, as reflected by increased B factors. Unwinding of the switch helix is proposed to be required for efficient binding of TonB to FhuA and for coupling the proton motive force of the cytoplasmic membrane with energy-dependent ligand transport. The transport data from cells expressing mutant FhuA proteins indicated conserved structural and mechanistic requirements for the transport of both types of compounds. CONCLUSIONS: We conclude that the binding of rifamycin CGP 4832 destabilizes the switch helix and promotes the formation of a transport-competent FhuA-TonB complex, albeit with lower efficiency than ferrichrome. Active transport of this rifamycin derivative explains the 200-fold increase in potency as compared to rifamycin, which is not a FhuA-specific ligand and permeates across the cell envelope by passive diffusion only.
+
The line below this paragraph, {{ABSTRACT_PUBMED_11587645}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 11587645 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_11587645}}
==About this Structure==
==About this Structure==
Line 39: Line 43:
[[Category: Siderophore receptor]]
[[Category: Siderophore receptor]]
[[Category: Tonb-dependent receptor]]
[[Category: Tonb-dependent receptor]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 16:20:58 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 1 03:16:41 2008''

Revision as of 00:16, 1 July 2008

Image:1fi1.png

Template:STRUCTURE 1fi1

FhuA in complex with lipopolysaccharide and rifamycin CGP4832

Template:ABSTRACT PUBMED 11587645

About this Structure

1FI1 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

Reference

Active transport of an antibiotic rifamycin derivative by the outer-membrane protein FhuA., Ferguson AD, Kodding J, Walker G, Bos C, Coulton JW, Diederichs K, Braun V, Welte W, Structure. 2001 Aug;9(8):707-16. PMID:11587645

Page seeded by OCA on Tue Jul 1 03:16:41 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1fi1"
Personal tools