TY - JOUR
T1 - Structural and functional studies of fatty acyl adenylate ligases from E. coli and L. pneumophila
AU - Zhang, Zhening
AU - Zhou, Rong
AU - Sauder, J. Michael
AU - Tonge, Peter J.
AU - Burley, Stephen K.
AU - Swaminathan, Subramanyam
N1 - Funding Information: Research was supported by a U54 award from the National Institute of General Medical Sciences to the New York SGX Research Center for Structural Genomics ( GM074945 , PI: S.K.B.) under DOE Prime Contract No. DEAC02-98CH10886 with Brookhaven National Laboratory and by National Institutes of Health grant AI044639 (PI: P.J.T.). We thank Drs. Howard Robinson and Anand Saxena for providing data collection facilities (X29 and X12C) at the National Synchrotron Light Source.
PY - 2011/2/18
Y1 - 2011/2/18
N2 - 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 Å, 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.
AB - 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 Å, 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.
KW - AMP
KW - CoA
KW - X-ray structure
KW - fatty acyl-AMP ligase
KW - fatty acyl-CoA ligase
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U2 - 10.1016/j.jmb.2010.12.011
DO - 10.1016/j.jmb.2010.12.011
M3 - Article
C2 - 21185305
SN - 0022-2836
VL - 406
SP - 313
EP - 324
JO - Journal of molecular biology
JF - Journal of molecular biology
IS - 2
ER -