Structural and Functional Studies of Fatty Acyl Adenylate Ligases from E. coli and L. pneumophila

Journal Article · Fri Feb 18 04:00:00 EST 2011 · Journal of Molecular Biology

DOI:https://doi.org/10.1016/j.jmb.2010.12.011· OSTI ID:1040583

Zhang, Z; Swaminathan, S; Zhou, R; Sauder, J M; Tonge, P J; Burley, S K

Fatty acyl-AMP ligase (FAAL) is a new member of a family of adenylate-forming enzymes that were recently discovered in Mycobacterium tuberculosis. They are similar in sequence to fatty acyl-coenzyme A (CoA) ligases (FACLs). However, while FACLs perform a two-step catalytic reaction, AMP ligation followed by CoA ligation using ATP and CoA as cofactors, FAALs produce only the acyl adenylate and are unable to perform the second step. We report X-ray crystal structures of full-length FAAL from Escherichia coli (EcFAAL) and FAAL from Legionella pneumophila (LpFAAL) bound to acyl adenylate, determined at resolution limits of 3.0 and 1.85 {angstrom}, respectively. The structures share a larger N-terminal domain and a smaller C-terminal domain, which together resemble the previously determined structures of FAAL and FACL proteins. Our two structures occur in quite different conformations. EcFAAL adopts the adenylate-forming conformation typical of FACLs, whereas LpFAAL exhibits a unique intermediate conformation. Both EcFAAL and LpFAAL have insertion motifs that distinguish them from the FACLs. Structures of EcFAAL and LpFAAL reveal detailed interactions between this insertion motif and the interdomain hinge region and with the C-terminal domain. We suggest that the insertion motifs support sufficient interdomain motions to allow substrate binding and product release during acyl adenylate formation, but they preclude CoA binding, thereby preventing CoA ligation.

• Research Organization: BROOKHAVEN NATIONAL LABORATORY (BNL)
• Sponsoring Organization: ELI LILLY & COMPANY
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1040583
• Report Number(s): BNL--95372-2011-JA; 600301010
• Journal Information: Journal of Molecular Biology, Journal Name: Journal of Molecular Biology Journal Issue: 2 Vol. 406; ISSN JMOBAK; ISSN 0022-2836
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
AMP
CRYSTAL STRUCTURE
CoA
ENZYMES
ESCHERICHIA COLI
LEGIONELLA PNEUMOPHILA
LIGASES
MYCOBACTERIUM TUBERCULOSIS
PROTEINS
RESOLUTION
SUBSTRATES
X-ray structure
fatty acyl-AMP ligase
fatty acyl-CoA ligase