E. coli aconitase B structure reveals a HEAT-like domain with implications for protein-protein recognition.
The major bifunctional aconitase of Escherichia coli (AcnB) serves as either an enzymic catalyst or a mRNA-binding post-transcriptional regulator, depending on the status of its iron sulfur cluster. AcnB represents a large, distinct group of Gram-negative bacterial aconitases that have an altered domain organization relative to mitochondrial aconitase and other aconitases. Here the 2.4 A structure of E. coli AcnB reveals a high degree of conservation at the active site despite its domain reorganization. It also reveals that the additional domain, characteristic of the AcnB subfamily, is a HEAT-like domain, implying a role in protein protein recognition. This domain packs against the remainder of the protein to form a tunnel leading to the aconitase active site, potentially for substrate channeling.
Williams
Colin H
CH
Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, UK.
Stillman
Timothy J
TJ
Barynin
Vladimir V
VV
Sedelnikova
Svetlana E
SE
Tang
Yue
Y
Green
Jeffrey
J
Guest
John R
JR
Artymiuk
Peter J
PJ
D000154:Aconitate Hydratase / Q000737:chemistry* / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D013329:Structure-Activity Relationship
D009097:Multienzyme Complexes; D016601:RNA-Binding Proteins; D012313:RNA; D000154:Aconitate Hydratase