A π-Helix Switch Selective for Porphyrin Deprotonation and Product Release in Human Ferrochelatase

Amy Elizabeth Medlock, Tamara A. Dailey, Teresa A. Ross, Harry A. Dailey, William N. Lanzilotta

Research output: Contribution to journalArticle

44 Citations (Scopus)

Abstract

Ferrochelatase (protoheme ferrolyase, EC 4.99.1.1) is the terminal enzyme in heme biosynthesis and catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme IX (heme). Due to the many critical roles of heme, synthesis of heme is required by the vast majority of organisms. Despite significant investigation of both the microbial and eukaryotic enzyme, details of metal chelation remain unidentified. Here we present the first structure of the wild-type human enzyme, a lead-inhibited intermediate of the wild-type enzyme with bound metallated porphyrin macrocycle, the product bound form of the enzyme, and a higher resolution model for the substrate-bound form of the E343K variant. These data paint a picture of an enzyme that undergoes significant changes in secondary structure during the catalytic cycle. The role that these structural alterations play in overall catalysis and potential protein-protein interactions with other proteins, as well as the possible molecular basis for these changes, is discussed. The atomic details and structural rearrangements presented herein significantly advance our understanding of the substrate binding mode of ferrochelatase and reveal new conformational changes in a structurally conserved π-helix that is predicted to have a central role in product release.

Original languageEnglish (US)
Pages (from-to)1006-1016
Number of pages11
JournalJournal of Molecular Biology
Volume373
Issue number4
DOIs
StatePublished - Nov 2 2007

Fingerprint

Ferrochelatase
Porphyrins
Heme
Enzymes
Proteins
Paint
Catalysis
Metals

Keywords

  • X-ray crystallography
  • ferrochelatase
  • heme synthesis
  • protoporphyrin IX

ASJC Scopus subject areas

  • Structural Biology
  • Molecular Biology

Cite this

A π-Helix Switch Selective for Porphyrin Deprotonation and Product Release in Human Ferrochelatase. / Medlock, Amy Elizabeth; Dailey, Tamara A.; Ross, Teresa A.; Dailey, Harry A.; Lanzilotta, William N.

In: Journal of Molecular Biology, Vol. 373, No. 4, 02.11.2007, p. 1006-1016.

Research output: Contribution to journalArticle

Medlock, Amy Elizabeth ; Dailey, Tamara A. ; Ross, Teresa A. ; Dailey, Harry A. ; Lanzilotta, William N. / A π-Helix Switch Selective for Porphyrin Deprotonation and Product Release in Human Ferrochelatase. In: Journal of Molecular Biology. 2007 ; Vol. 373, No. 4. pp. 1006-1016.
@article{f06a4f0a3f0b4e8ba5a204218792c233,
title = "A π-Helix Switch Selective for Porphyrin Deprotonation and Product Release in Human Ferrochelatase",
abstract = "Ferrochelatase (protoheme ferrolyase, EC 4.99.1.1) is the terminal enzyme in heme biosynthesis and catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme IX (heme). Due to the many critical roles of heme, synthesis of heme is required by the vast majority of organisms. Despite significant investigation of both the microbial and eukaryotic enzyme, details of metal chelation remain unidentified. Here we present the first structure of the wild-type human enzyme, a lead-inhibited intermediate of the wild-type enzyme with bound metallated porphyrin macrocycle, the product bound form of the enzyme, and a higher resolution model for the substrate-bound form of the E343K variant. These data paint a picture of an enzyme that undergoes significant changes in secondary structure during the catalytic cycle. The role that these structural alterations play in overall catalysis and potential protein-protein interactions with other proteins, as well as the possible molecular basis for these changes, is discussed. The atomic details and structural rearrangements presented herein significantly advance our understanding of the substrate binding mode of ferrochelatase and reveal new conformational changes in a structurally conserved π-helix that is predicted to have a central role in product release.",
keywords = "X-ray crystallography, ferrochelatase, heme synthesis, protoporphyrin IX",
author = "Medlock, {Amy Elizabeth} and Dailey, {Tamara A.} and Ross, {Teresa A.} and Dailey, {Harry A.} and Lanzilotta, {William N.}",
year = "2007",
month = "11",
day = "2",
doi = "10.1016/j.jmb.2007.08.040",
language = "English (US)",
volume = "373",
pages = "1006--1016",
journal = "Journal of Molecular Biology",
issn = "0022-2836",
publisher = "Academic Press Inc.",
number = "4",

}

TY - JOUR

T1 - A π-Helix Switch Selective for Porphyrin Deprotonation and Product Release in Human Ferrochelatase

AU - Medlock, Amy Elizabeth

AU - Dailey, Tamara A.

AU - Ross, Teresa A.

AU - Dailey, Harry A.

AU - Lanzilotta, William N.

PY - 2007/11/2

Y1 - 2007/11/2

N2 - Ferrochelatase (protoheme ferrolyase, EC 4.99.1.1) is the terminal enzyme in heme biosynthesis and catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme IX (heme). Due to the many critical roles of heme, synthesis of heme is required by the vast majority of organisms. Despite significant investigation of both the microbial and eukaryotic enzyme, details of metal chelation remain unidentified. Here we present the first structure of the wild-type human enzyme, a lead-inhibited intermediate of the wild-type enzyme with bound metallated porphyrin macrocycle, the product bound form of the enzyme, and a higher resolution model for the substrate-bound form of the E343K variant. These data paint a picture of an enzyme that undergoes significant changes in secondary structure during the catalytic cycle. The role that these structural alterations play in overall catalysis and potential protein-protein interactions with other proteins, as well as the possible molecular basis for these changes, is discussed. The atomic details and structural rearrangements presented herein significantly advance our understanding of the substrate binding mode of ferrochelatase and reveal new conformational changes in a structurally conserved π-helix that is predicted to have a central role in product release.

AB - Ferrochelatase (protoheme ferrolyase, EC 4.99.1.1) is the terminal enzyme in heme biosynthesis and catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme IX (heme). Due to the many critical roles of heme, synthesis of heme is required by the vast majority of organisms. Despite significant investigation of both the microbial and eukaryotic enzyme, details of metal chelation remain unidentified. Here we present the first structure of the wild-type human enzyme, a lead-inhibited intermediate of the wild-type enzyme with bound metallated porphyrin macrocycle, the product bound form of the enzyme, and a higher resolution model for the substrate-bound form of the E343K variant. These data paint a picture of an enzyme that undergoes significant changes in secondary structure during the catalytic cycle. The role that these structural alterations play in overall catalysis and potential protein-protein interactions with other proteins, as well as the possible molecular basis for these changes, is discussed. The atomic details and structural rearrangements presented herein significantly advance our understanding of the substrate binding mode of ferrochelatase and reveal new conformational changes in a structurally conserved π-helix that is predicted to have a central role in product release.

KW - X-ray crystallography

KW - ferrochelatase

KW - heme synthesis

KW - protoporphyrin IX

UR - http://www.scopus.com/inward/record.url?scp=34848852657&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34848852657&partnerID=8YFLogxK

U2 - 10.1016/j.jmb.2007.08.040

DO - 10.1016/j.jmb.2007.08.040

M3 - Article

C2 - 17884090

AN - SCOPUS:34848852657

VL - 373

SP - 1006

EP - 1016

JO - Journal of Molecular Biology

JF - Journal of Molecular Biology

SN - 0022-2836

IS - 4

ER -