Figure 6

Neighbour-joining tree of the PARP domains of the plant SRO protein family. The PARP domains of the SRO proteins from the sequenced genomes of A. thaliana, A. lyrata, Vitis vinifera, Ricinus communis, Populus trichocarpa, Oryza sativa ssp. japonica, Brachypodium distachyon, Physcomitrella patens and Selaginella moellendorffi were identified and aligned. Subsequently, a Neighbour-joining phylogenetic tree was constructed using MEGA4. AtPARP1, 2 and 3 were used as outgroups. Plant SROs could be classified into two groups. Group I contained SROs from all included plant species and could be further divided into three subgroups (Ia, Ib and Ic) according to the C-terminal RST domain. Most SROs in group I belonged to structural type A. The members of group II (a and b) without exception belonged to structural type B.