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 named:

Sirohaem synthase, dimerisation domain

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.

Superfamily: Sirohaem synthase, dimerisation domain

Bacterial sulphur metabolism depends on the iron-containing porphinoid sirohaem. CysG is a multi-functional siroheme synthase with S-adenosyl-L-methionine (SAM)-dependent bismethyltransferase, dehydrogenase and ferrochelatase activities. CysG synthesises sirohaem from uroporphyrinogen III via reactions which encompass two branchpoint intermediates in tetrapyrrole biosynthesis, diverting flux first from protoporphyrin IX biosynthesis and then from cobalamin (vitamin B12) biosynthesis.

CysG is a homodimeric gene fusion product, and this superfamily entry represents the dimerisation domain of CysG. The dimerisation region acts to hold the two structurally similar protomers held together asymmetrically through a number of salt-bridges across complementary residues within the dimerisation region. CysG dimerisation produces a series of active sites, accounting for CysG's multi-functionality, catalysing four diverse reactions, such as SAM-dependent methylation, NAD+-dependent tetrapyrrole dehydrogenation and metal chelation.

PFAM:PF10414, INTERPRO:IPR037115,DOI:10.1038/nsb1007PMID:14595395

GO Diversity

Unique GO annotations
4 Unique GO terms

EC Diversity

Unique EC annotations
6 Unique EC terms

Species Diversity

Unique species annotations
2858 Unique species

Sequence/Structure Diversity

Overview of the sequence / structure diversity of this superfamily compared to other superfamilies in CATH. Click on the chart to view the data in more detail.

Superfamily Summary

A general summary of information for this superfamily.
Domains: 6
Domain clusters (>95% seq id): 1
Domain clusters (>35% seq id): 1
Unique PDBs: 3
Structural Clusters (5A): 1
Structural Clusters (9A): 1
FunFam Clusters: 10
Unique EC: 6
Unique GO: 4
Unique Species: 2858