Table1. List of sequences included in the DPE2 phylogenetic analysis, accession numbers and full species names are included. Sequences are sorted by taxonomic group, then by species name. DPE2-like sequences that possess introns in the genomic sequences are indicated.

Species	Accession	Introns	Taxon
Arabidopsis lyrata	XP_002879894.1	yes	chloroplastida
Arabidopsis thaliana	AAL91204.1	yes	chloroplastida
Carica papaya	evm.TU.supercontig_92.60	yes	chloroplastida
Chlamydomonas reinhardtii	XP_001701179.1	yes	chloroplastida
Micromonas sp RCC299	ACO70268.1	yes	chloroplastida
Oryza sativa Japonica Group	NP_001060547.1	yes	chloroplastida
Ostreococcus lucimarinus CCE9901	ABO98795.1	yes	chloroplastida
Physcomitrella patens subsp patens	XP_001779217.1	yes	chloroplastida
Populus trichocarpa	XP_002323208.1	yes	chloroplastida
Populus trichocarpa	XP_002308854.1	yes	chloroplastida
Ricinus communis	XP_002523669.1	yes	chloroplastida
Selaginella moellendorffii	XP_002979331.1	yes	chloroplastida
Selaginella moellendorffii	XP_002988641.1	yes	chloroplastida
Sorghum bicolor	XP_002461165.1	yes	chloroplastida
Vitis vinifera	XP_002278329.1	yes	chloroplastida
Volvox carteri f. nagariensis	XP_002956849.1	yes	chloroplastida
Dictyostelium discoideum AX4 AX4	EAL65318.1	yes	amoebozoa
Dictyostelium purpureum	XP_003286541.1	yes	amoebozoa
Polysphondylium pallidum PN500	EFA84397.1	yes	amoebozoa
Entamoeba dispar SAW760	EDR24789.1	no	amoebozoa
Entamoeba histolytica HM-1:IMSS	EAL52093.1	no	amoebozoa
Giardia intestinalis ATCC 50581	EET00671.1	no	metamonada
Giardia lamblia ATCC 50803	XP_001709888.1	no	metamonada
Trichomonas vaginalis G3 ATCC PRA-98	EAX97809.1	no	metamonada
Cyanidioschyzon merolae	CMT204C	no	rhodophyte
Cyanidioschyzon merolae	CMP352C	no	rhodophyte
Galderia sulphuraria	Gs34050.1	no	rhodophyte
Calliarthron tuberculosum	contig_2_67557	no	rhodophyte
Porphyridium cruentum	Contig14123	no	rhodophyte
Porphyridium cruentum	Contig9269	no	rhodophyte
Alistipes shahii WAL 8301	CBK62792.1	-	bacteroidetes (gut)
Bacteroides caccae ATCC 43185	ZP_01961413.1	-	bacteroidetes (gut)
Bacteroides coprocola DSM 17136	ZP_03011722.1	-	bacteroidetes (gut)
Bacteroides coprophilus DSM 18228	ZP_03643552.1	-	bacteroidetes (gut)
Bacteroides eggerthii DSM 20697	ZP_03457421.1	-	bacteroidetes (gut)
Bacteroides finegoldii DSM 17565	ZP_05415079.1	-	bacteroidetes (gut)
Bacteroides fragilis NCTC 9343	YP_213214.1	-	bacteroidetes (gut)
Bacteroides ovatus ATCC 8483	ZP_02066204.1	-	bacteroidetes (gut)
Bacteroides stercoris ATCC 43183	ZP_02436972.1	-	bacteroidetes (gut)
Bacteroides thetaiotaomicron VPI-5482	AAO77253.1	-	bacteroidetes (gut)
Bacteroides uniformis ATCC 8492	EDO54757.1	-	bacteroidetes (gut)
Bacteroides vulgatus ATCC 8482	ABR39076.1	-	bacteroidetes (gut)
Bacteroides xylanisolvens XB1A	CBK66288.1	-	bacteroidetes (gut)
Haliscomenobacter hydrossis DSM 1100	AEE47959.1	-	bacteroidetes (environmental)
Paludibacter propionicigenes WB4	ADQ79431.1	-	bacteroidetes (environmental)
Flavobacteriaceae bacterium 3519–10	ACU06866.1	-	bacteroidetes (environmental)
Chryseobacterium gleum ATCC 35910	ZP_07084258.1	-	bacteroidetes (vagina)
Parabacteroides distasonis ATCC 8503	ABR41798.1	-	bacteroidetes (gut)
Parabacteroides johnsonii DSM 18315	ZP_03478180.1	-	bacteroidetes (gut)
Parabacteroides merdae ATCC 43184	ZP_02031326.1	-	bacteroidetes (gut)
Porphyromonas gingivalis W83	BAG33312.1	-	bacteroidetes (gut)
Prevotella bergensis DSM 17361	ZP_06005569.1	-	bacteroidetes (gut)
Prevotella bivia JCVIHMP010	ZP_06267844.1	-	bacteroidetes (gut)
Prevotella bryantii	ZP_07061030.1	-	bacteroidetes (gut)
Prevotella buccae D17	ZP_06419222.1	-	bacteroidetes (gut)
Prevotella copri DSM 18205	ZP_06252955.1	-	bacteroidetes (gut)
Prevotella disiens FB035–09AN	ZP_07323182.1	-	bacteroidetes (gut)
Prevotella marshii DSM 16973	ZP_07366273.1	-	bacteroidetes (gut)
Prevotella melaninogenica ATCC 25845	ADK95815.1	-	bacteroidetes (gut)
Prevotella oris F0302	ZP_06254330.1	-	bacteroidetes (gut)
Prevotella timonensis CRIS 5C-B1	ZP_06289177.1	-	bacteroidetes (gut)
Prevotella veroralis F0319	ZP_05857248.1	-	bacteroidetes (gut)
Succinatimonas hippei YIT 12066	ZP_08077820.1	-	bacteroidetes (gut)