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CATH Superfamily 3.90.550.10

Spore Coat Polysaccharide Biosynthesis Protein SpsA; Chain A

The name of this superfamily has been modified since the most recent official CATH+ release (v4_3_0). At the point of the last release, this superfamily was named:

"
Spore Coat Polysaccharide Biosynthesis Protein SpsA; Chain A
".

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.
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FunFam 626: Adenosylcobinamide-phosphate guanylyltransferase

There are 1 EC terms in this cluster

Please note: EC annotations are assigned to the full protein sequence rather than individual protein domains. Since a given protein can contain multiple domains, it is possible that some of the annotations below come from additional domains that occur in the same protein, but have been classified elsewhere in CATH.

Note: The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.

EC Term Annotations Evidence
Adenosylcobinamide-phosphate guanylyltransferase. [EC: 2.7.7.62]
GTP + adenosylcobinamide phosphate = diphosphate + adenosylcobinamide- GDP.
  • In Salmonella typhimurium LT2, under anaerobic conditions, CobU (EC 2.7.7.62 and EC 2.7.1.156), CobT (EC 2.4.2.21), CobC (EC 3.1.3.73) and CobS (EC 2.7.8.26) catalyze reactions in the nucleotide loop assembly pathway, which convert adenosylcobinamide (AdoCbi) into adenosylcobalamin (AdoCbl).
  • CobT and CobC are involved in 5,6-dimethylbenzimidazole activation whereby 5,6-dimethylbenzimidazole is converted to its riboside, alpha-ribazole.
  • The second branch of the nuclotide loop assembly pathway is the cobinamide (Cbi) activation branch where AdoCbi or adenosylcobinamide-phosphate is converted to the activated intermediate AdoCbi-GDP by the bifunctional enzyme CobU.
  • The final step in adenosylcobalamin biosynthesis is the condensation of AdoCbi-GDP with alpha-ribazole, which is catalyzed by CobS (EC 2.7.8.26), to yield adenosylcobalamin.
  • CobU is a bifunctional enzyme that has both kinase (EC 2.7.1.156) and guanylyltransferase (EC 2.7.7.62) activities.
  • However, both activities are not required at all times.
  • The kinase activity has been proposed to function only when S.typhimurium is assimilating cobinamide whereas the guanylyltransferase activity is required for both assimilation of exogenous cobinamide and for de novo synthesis of adenosylcobalamin.
  • The guanylyltransferase reaction is a two-stage reaction with formation of a CobU-GMP intermediate.
 1 Q58517