Discovery of a Unique Structural Motif in Lanthipeptide Synthetases for Substrate Binding and Interdomain Interactions

Abstract

Class III lanthipeptide synthetases catalyze the formation of lanthionine/methyllanthionine and labionin crosslinks. We present here the 2.40 Å resolution structure of the kinase domain of a class III lanthipeptide synthetase CurKC from the biosynthesis of curvopeptin. A unique structural subunit for leader binding, named leader recognition domain (LRD), was identified. The LRD of CurKC is responsible for the recognition of the leader peptide and for mediating interactions between the lyase and kinase domains. LRDs are highly conserved among the kinase domains of class III and class IV lanthipeptide synthetases. The discovery of LRDs provides insight into the substrate recognition and domain organization in multidomain lanthipeptide synthetases.

Discovery of the Lanthipeptide Curvocidin and Structural Insights into its Trifunctional Synthetase CuvL

“…The structure of the excised kinase domain of the class‐III synthetase CurKC from T. curvata bound to adenosine has been recently reported [21a] . The authors proposed the N‐lobe as a major LP binding region of CurKC and indicated that native lyase‐kinase domain contacts are required to recruit the LP efficiently.…”

“…Helices α2 K , α4 K , α5 K and the interjacent loops are deployed to settle on the C‐terminal cyclase domain. The largest difference to the structure of the excised CurKC kinase domain [21a] is the reorganization of α‐helices α5 K ‐α7 K including their outward translation to form the interface with the cyclase domain. The latter is connected to the C‐lobe by a proline‐rich linker (P‐linker, Pro475‐Pro480) adopting a polyproline helix II (PPII) conformation (Figure 3).…”

“…[16,19] While RiPP biosynthesis is varied, hydrophobic interactions appear to play an important role in molecular recognition of LPs. [7,21] Analysis of LP sequences suggests short hydrophobic packing motifs to be critical for LP recruitment. [10b, [20][21][22] For example, LPs of class-I, -II and -III lanthipeptides have been reported to display α-helical character in solution.…”

“…[7,21] Analysis of LP sequences suggests short hydrophobic packing motifs to be critical for LP recruitment. [10b, [20][21][22] For example, LPs of class-I, -II and -III lanthipeptides have been reported to display α-helical character in solution. [20,23] However, in the case of the class-I lanthipeptide nisin, the LP of NisA adopted β-strand conformation when bound to the RRE of NisB.…”

Mechanistic Investigations into the Catalytic Mode of a Dehydratase Complex Involved in the Biosynthesis of Lantibiotic Cacaoidin

“…[ 6 ] Recent structural studies have revealed that in both LanKC and LanL, the phosphotransferase domain couples with the lyase domain and leader peptide (LP), facilitating the efficient transfer of the phosphorylated core peptide (CP) to the cavity of the lyase domain. [ 7 ]…”