Figure 1

The arrangement of genes and open reading frames (ORFs) within various major geminivirus lineages. BCTIV = beet curley top Iran virus. ECSV = Eragrostis curvula streak virus (reported for the first time in this paper). In the case of begomoviruses only the DNA-A/DNA-A-like genome component sequence is represented. Arrows indicate the positions and orientations of numbered ORFs (V = virion sense and C = complementary sense) that are known or strongly suspected to encode expressed proteins. mp = movement protein gene [4–7], cp = coat protein gene, rep = replication associated protein gene, ren = replication enhancer gene, trap = transcription activator protein gene, ss = silencing suppressor encoding ORF [8–14], sd = symptom determinant encoding ORF [15, 16]; reg = potentially encoding a protein that regulates relative ssDNA and dsDNA concentrations [4]. A question mark indicates that an ORFs function is either completely unknown or only suspected. The only genes shared between all genomes are rep (in blue) and cp (in red). Variations in the presence or size of ORFs between members of the different geminivirus groups are indicated in grey. Intergenic regions are represented as open blocks and the probable hairpin structure at the origin of virion strand replication is indicated at the 12 o'clock position.