Enzymes
| UniProtKB help_outline | 561 proteins |
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Reaction participants Show >> << Hide
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,431 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline hydrogen sulfide Identifier CHEBI:29919 (CAS: 15035-72-0) help_outline Charge -1 Formula HS InChIKeyhelp_outline RWSOTUBLDIXVET-UHFFFAOYSA-M SMILEShelp_outline [S-][H] 2D coordinates Mol file for the small molecule Search links Involved in 56 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
O-phospho-L-seryl-tRNACys
Identifier
RHEA-COMP:9719
Reactive part
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- Name help_outline 3'-(O-phosphonato-L-seryl)adenylyl group Identifier CHEBI:78551 Charge -2 Formula C13H17N6O11P2 SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](COP([O-])(-*)=O)[C@@H](OC(=O)[C@@H]([NH3+])COP([O-])([O-])=O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 4 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
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Namehelp_outline
L-cysteinyl-tRNACys
Identifier
RHEA-COMP:9679
Reactive part
help_outline
- Name help_outline 3'-(L-cysteinyl)adenylyl group Identifier CHEBI:78517 Charge 0 Formula C13H18N6O7PS SMILEShelp_outline Nc1ncnc2n(cnc12)[C@@H]1O[C@H](COP([O-])(-*)=O)[C@@H](OC(=O)[C@@H]([NH3+])CS)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 4 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline phosphate Identifier CHEBI:43474 Charge -2 Formula HO4P InChIKeyhelp_outline NBIIXXVUZAFLBC-UHFFFAOYSA-L SMILEShelp_outline OP([O-])([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 992 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:25686 | RHEA:25687 | RHEA:25688 | RHEA:25689 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Redundant synthesis of cysteinyl-tRNACys in Methanosarcina mazei.
Hauenstein S.I., Perona J.J.
A subset of methanogenic archaea synthesize the cysteinyl-tRNA(Cys) (Cys-tRNA(Cys)) needed for protein synthesis using both a canonical cysteinyl-tRNA synthetase (CysRS) as well as a set of two enzymes that operate via a separate indirect pathway. In the indirect route, phosphoseryl-tRNA(Cys) (Sep ... >> More
A subset of methanogenic archaea synthesize the cysteinyl-tRNA(Cys) (Cys-tRNA(Cys)) needed for protein synthesis using both a canonical cysteinyl-tRNA synthetase (CysRS) as well as a set of two enzymes that operate via a separate indirect pathway. In the indirect route, phosphoseryl-tRNA(Cys) (Sep-tRNA(Cys)) is first synthesized by phosphoseryl-tRNA synthetase (SepRS), and this misacylated intermediate is then converted to Cys-tRNA(Cys) by Sep-tRNA:Cys-tRNA synthase (SepCysS) via a pyridoxal phosphate-dependent mechanism. Here, we explore the function of all three enzymes in the mesophilic methanogen Methanosarcina mazei. The genome of M. mazei also features three distinct tRNA(Cys) isoacceptors, further indicating the unusual and complex nature of Cys-tRNA(Cys) synthesis in this organism. Comparative aminoacylation kinetics by M. mazei CysRS and SepRS reveals that each enzyme prefers a distinct tRNA(Cys) isoacceptor or pair of isoacceptors. Recognition determinants distinguishing the tRNAs are shown to reside in the globular core of the molecule. Both enzymes also require the S-adenosylmethione-dependent formation of (m1)G37 in the anticodon loop for efficient aminoacylation. We further report a new, highly sensitive assay to measure the activity of SepCysS under anaerobic conditions. With this approach, we demonstrate that SepCysS functions as a multiple-turnover catalyst with kinetic behavior similar to bacterial selenocysteine synthase and the archaeal/eukaryotic SepSecS enzyme. Together, these data suggest that both metabolic routes and all three tRNA(Cys) species in M. mazei play important roles in the cellular physiology of the organism. << Less
J Biol Chem 283:22007-22017(2008) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.
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Structural insights into the second step of RNA-dependent cysteine biosynthesis in archaea: crystal structure of Sep-tRNA:Cys-tRNA synthase from Archaeoglobus fulgidus.
Fukunaga R., Yokoyama S.
In the ancient organisms, methanogenic archaea, lacking the canonical cysteinyl-tRNA synthetase, Cys-tRNA(Cys) is produced by an indirect pathway, in which O-phosphoseryl-tRNA synthetase ligates O-phosphoserine (Sep) to tRNA(Cys) and Sep-tRNA:Cys-tRNA synthase (SepCysS) converts Sep-tRNA(Cys) to C ... >> More
In the ancient organisms, methanogenic archaea, lacking the canonical cysteinyl-tRNA synthetase, Cys-tRNA(Cys) is produced by an indirect pathway, in which O-phosphoseryl-tRNA synthetase ligates O-phosphoserine (Sep) to tRNA(Cys) and Sep-tRNA:Cys-tRNA synthase (SepCysS) converts Sep-tRNA(Cys) to Cys-tRNA(Cys). In this study, the crystal structure of SepCysS from Archaeoglobus fulgidus has been determined at 2.4 A resolution. SepCysS forms a dimer, composed of monomers bearing large and small domains. The large domain harbors the seven-stranded beta-sheet, which is typical of the pyridoxal 5'-phosphate (PLP)-dependent enzymes. In the active site, which is located near the dimer interface, PLP is covalently bound to the side-chain of the conserved Lys209. In the proximity of PLP, a sulfate ion is bound by the side-chains of the conserved Arg79, His103, and Tyr104 residues. The active site is located deep within the large, basic cleft to accommodate Sep-tRNA(Cys). On the basis of the surface electrostatic potential, the amino acid residue conservation mapping, the position of the bound sulfate ion, and the substrate amino acid binding manner in other PLP-dependent enzymes, a binding model of Sep-tRNA(Cys) to SepCysS was constructed. One of the three strictly conserved Cys residues (Cys39, Cys42, or Cys247), of one subunit may play a crucial role in the catalysis in the active site of the other subunit. << Less
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RNA-dependent conversion of phosphoserine forms selenocysteine in eukaryotes and archaea.
Yuan J., Palioura S., Salazar J.C., Su D., O'Donoghue P., Hohn M.J., Cardoso A.M., Whitman W.B., Soell D.
The trace element selenium is found in proteins as selenocysteine (Sec), the 21st amino acid to participate in ribosome-mediated translation. The substrate for ribosomal protein synthesis is selenocysteinyl-tRNA(Sec). Its biosynthesis from seryl-tRNA(Sec) has been established for bacteria, but the ... >> More
The trace element selenium is found in proteins as selenocysteine (Sec), the 21st amino acid to participate in ribosome-mediated translation. The substrate for ribosomal protein synthesis is selenocysteinyl-tRNA(Sec). Its biosynthesis from seryl-tRNA(Sec) has been established for bacteria, but the mechanism of conversion from Ser-tRNA(Sec) remained unresolved for archaea and eukarya. Here, we provide evidence for a different route present in these domains of life that requires the tRNA(Sec)-dependent conversion of O-phosphoserine (Sep) to Sec. In this two-step pathway, O-phosphoseryl-tRNA(Sec) kinase (PSTK) converts Ser-tRNA(Sec) to Sep-tRNA(Sec). This misacylated tRNA is the obligatory precursor for a Sep-tRNA:Sec-tRNA synthase (SepSecS); this protein was previously annotated as SLA/LP. The human and archaeal SepSecS genes complement in vivo an Escherichia coli Sec synthase (SelA) deletion strain. Furthermore, purified recombinant SepSecS converts Sep-tRNA(Sec) into Sec-tRNA(Sec) in vitro in the presence of sodium selenite and purified recombinant E. coli selenophosphate synthetase (SelD). Phylogenetic arguments suggest that Sec decoding was present in the last universal common ancestor. SepSecS and PSTK coevolved with the archaeal and eukaryotic lineages, but the history of PSTK is marked by several horizontal gene transfer events, including transfer to non-Sec-decoding Cyanobacteria and fungi. << Less
Proc. Natl. Acad. Sci. U.S.A. 103:18923-18927(2006) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.