The name of this superfamily has been modified since the most recent official CATH+ release (v4_2_0). At the point of the last release, this superfamily was: waiting to be named.
Luciferases are composed of a large N-terminal domain and a smaller C-terminal domain, which form a cleft. The active site of these enzymes is located at the interface between these two domains, with most active site residues located in the N-terminal domain, and two lysine residues in the C-terminal domain. The N-terminal domain is involved in catalysis, and the C-terminal domain is essential for luciferase activation during the catalytic reaction.
The overall structure of the N-terminal domain has been characterised in a fatty acyl-CoA ligase in M. tuberculosis, FA[PfamClan:CL13] and fatty acyl-AMP ligase FAAL28. The N-terminal domain of FA[PfamClan:CL13] consists of three subdomains: subdomains A and B form alpha + beta topology, which pack together to form a five-layered alpha-beta-alpha-beta-alpha tertiary structure. The third subdomain C folds into a distorted beta-barrel topology. In FAAL28, the C-subdomain presents an insertion between beta-strands 1 and 2. A hydrophobic interaction was identified at the interface of insertion and N-terminal domain, and it was suggested to play a fundamental role in anchoring the insertion motif and arresting the acyl-CoA catalysis. The C-terminal domain can adopt two different conformations which allow the catalysis to occur in two steps. After the adenylation step in 'adenylation conformation', the C-terminal domain undergoes a domain alternation of 140 degrees to adopt a 'thiolation conformation' required for the second step of catalysis.
The Mycobacterium tuberculosis fatty acyl-CoA synthetase (ACS) FadD13 is a peripheral membrane protein essential for virulence and intracellular growth of the pathogen. FadD13 was identified to play a central role in lipid metabolism, and therefore would be a possible drug target. FadD13 comprises an N- and a C-terminal domain. The N-terminal domain folds into an alpha+beta topology and can be further divided into two subdomains. The CoA binding site in ACS proteins is formed in the junction between the domains upon a 140 degrees rotation of the C-terminal domain after the initial adenylation step.
|Domain clusters (>95% seq id):||54|
|Domain clusters (>35% seq id):||30|
|Structural Clusters (5A):||1|
|Structural Clusters (9A):||1|