InterPro domain: IPR044685

General Information

  • Identifier IPR044685
  • Description Protein ACCUMULATION AND REPLICATION OF CHLOROPLASTS 6-like
  • Number of genes 260
  • Gene duplication stats Loading...

Abstract

This family represents plant Protein ACCUMULATION AND REPLICATION OF CHLOROPLASTS 6 (ARC6) and its paralogue PARC6, components of the plastid division machinery which are essential for the chloroplast replication process [ 1 , 2 ]. ARC6 is evolutionarily related to the cyanobacterial cell division protein Ftn2/ZipN [ 3 ], being unique to the division machineries of cyanobacteria and chloroplasts. Their sequences share about 19% identity and are quite conserved along their length. Chloroplast division implies the assembly and constriction of the tubulin-like FtsZ ring on the stromal surface of the inner envelope membrane (IEM) and the dynamin-like ARC5 ring on the cytosolic surface of the outer envelope membrane (OEM). The assembly of these structures is coordinated by a pair of paralogous proteins, ARC6 and PARC6 from the IEM, and PDV2 and PDV1 from the OEM. They contain single transmembrane (TM) domains towards their C terminus with short C‐terminal regions extending into the intermembrane space (IMS) [ 3 , 3 , 3 , 4 , 5 ].

Crystal structure of ARC6 showed that it comprises a chloroplast transit peptide, cleaved after chloroplast localisation, followed by a stroma‐facing, a transmembrane and IMS regions. The C-terminal IMS is highly conserved in ARC6 and Ftn2 proteins [ 6 ]. ARC6 interacts with FtsZ and PDV2 through its stromal and IMS regions, respectively. ARC6-PDV2 interaction is key for PDV2 localisation to the division site and to specify the site of ARC5 recruitment [ 6 ]. PARC6 and PDV1 interact and function in the same way as ARC6-PDV2 [ 6 , 6 ].

This entry also includes ARC6 homologues from cyanobacteria.


1. Crystal structure of a conserved domain in the intermembrane space region of the plastid division protein ARC6. Protein Sci 25, 523-9
2. Roles of Arabidopsis PARC6 in Coordination of the Chloroplast Division Complex and Negative Regulation of FtsZ Assembly. Plant Physiol 170, 250-62
3. ARC6 is a J-domain plastid division protein and an evolutionary descendant of the cyanobacterial cell division protein Ftn2. Plant Cell 15, 1918-33
4. Arabidopsis ARC6 coordinates the division machineries of the inner and outer chloroplast membranes through interaction with PDV2 in the intermembrane space. Plant Cell 20, 2460-70
5. Arabidopsis PARC6 Is Critical for Plastid Morphogenesis in Pavement, Trichome, and Guard Cells in Leaf Epidermis. Front Plant Sci 10, 1665

Species distribution

Gene table