A versatile cis-prenyltransferase from Methanosarcina mazei catalyzes both C- and O-prenylations

Abstract

Polyprenyl groups, products of isoprenoid metabolism, are utilized in peptidoglycan biosynthesis, protein N -glycosylation, and other processes. These groups are formed by cis -prenyltransferases, which use allylic prenyl pyrophosphates as prenyl-donors to catalyze the C -prenylation of the general acceptor substrate, isopentenyl pyrophosphate. Repetition of this reaction forms ( Z,E -mixed)-polyprenyl pyrophosphates, which are converted later into glycosyl carrier lipids, such as undecaprenyl phosphate and dolichyl phosphate. MM_0014 from the methanogenic archaeon Methanosarcina mazei is known as a versatile cis -prenyltransferase that accepts both isopentenyl pyrophosphate and dimethylallyl pyrophosphate as acceptor substrates. To learn more about this enzyme’s catalytic activity, we determined the X-ray crystal structures of MM_0014 in the presence or absence of these substrates. Surprisingly, one structure revealed a complex with O -prenylglycerol, suggesting that the enzyme catalyzed the prenylation of glycerol contained in the crystallization buffer. Further analyses confirmed that the enzyme could catalyze the O -prenylation of small alcohols, such as 2-propanol, expanding our understanding of the catalytic ability of cis -prenyltransferases.

Structural‐Functional Correlations between Unique N‐terminal Region and C‐terminal Conserved Motif in Short‐chain cis‐Prenyltransferase from Tomato

“…Instead, the cPTL family that functions as a regulatory subunit of L‐cPT contains an RXG motif, although in some cases the first Arg residue in this motif is substituted with Asn. Similar substitutions from the conserved Arg to Asn residues have been observed in the C‐terminal regions of archaeal M‐cPTs [15] . The crystal structure of ( Z,Z )‐FPP (C 15 ) synthase (zFPS), an S‐cPT from wild tomato, revealed that the RXG motif interacts with IPP near the S2 site, although the crystal structure was solved as an unusual complex that binds the IPP‐Mg 2+ ‐IPP complex at the active site [16] .…”

“…Similar substitutions from the conserved Arg to Asn residues have been observed in the C-terminal regions of archaeal M-cPTs. [15] The crystal structure of (Z,Z)-FPP (C 15 ) synthase (zFPS), an S-cPT from wild tomato, revealed that the RXG motif interacts with IPP near the S2 site, although the crystal structure was solved as an unusual complex that binds the IPP-Mg 2 + -IPP complex at the active site. [16] A mutagenesis study in the same report indicated that mutations in the RXG motif resulted in a significant loss of condensation activity in zFPS.…”

Complexation and evolution of cis‐prenyltransferase homologues in Cinnamomum kanehirae deduced from kinetic and functional characterizations

“…For example, MA1831 from Methanosarcina acetivorans and MM0014 from Methanosarcina mazei are UPPS orthologs, but their functions differ from UPPS, and both of them do not possess the common C‐terminal RXG motif (Figure 7). MA1831 could catalyze non‐canonical head‐to‐middle condensation and produce C35–C50 products, while MM0014 could yield C25–C40 products and have O‐prenyltransferase activity (Ogawa et al, 2016; Okada et al, 2021). Besides, the heteromeric cis‐PT homologues from Archaeoglobus fulgidus , a thermophilic archaeon, were recently biochemically characterized (Sompiyachoke et al, 2022).…”