Mitochondrial-encoded membrane protein transcripts are pyrimidine-rich while soluble protein transcripts and ribosomal RNA are purine-rich

Table 1 The number of genes that obey the rules of mitochondrial pyrimidine-purine base composition. All oxidative phosphorylation complex protein genes were included as membrane protein genes. Soluble mitochondrial protein genes included those of ribosomal proteins, maturases and endonucleases from intronic ORFs, and polymerase-like proteins. Unknown ORFs, hypothetical proteins, and proteins of unknown localization were excluded from the analysis. Transcripts that do not follow Rule #1 include almost all Dictyostelium transcripts, Chondrus crispus SDH2, Porphyra purpurea SDH2, COX2, and ymf39, Marchantia polymorpha NAD7 and ATPa, and Arabidopsis NAD7, NAD9, and ATP1. The Chlamydomonas reinhardtii rtl transcript breaks Rule #3.

	Organism Name		Rule 1	Rule 2	Rule 3	Hypothetical Proteins or Unknown Localization
Genbank Accession	Latin	Common	Holds (Fails)	Holds (Fails)	Holds (Fails)
[NC_001807]	Homo sapiens	Human	12 (1)	2	-	-
[NC_005089]	Mus musculus	Mouse	12 (1)	2	-	-
[NC_001913]	Oryctolagus cuniculus	Rabbit	12 (1)	2	-	-
[NC_002008]	Canis familiaris	Dog	13	2	-	-
[NC_000845]	Sus scrofa	Pig	13	2	-	-
[NC_001323]	Gallus gallus	Chicken	13	2	-	-
[NC_002784]	Dromaius novaehollandiae	Emu	13	2	-	-
[NC_001573]	Xenopus laevis	Frog	13	2	-	-
[NC_002333]	Danio rerio	Zebrafish	13	2	-	-
[NC_001709]	Drosophila melanogaster	Fruit fly	13	2	-	-
[NC_002074]	Rhipicephalus sanguineus	Brown dog tick	13	2	-	-
[NC_003344]	Thyropygus sp. DVL-2001	Giant millipede	13	2	-	-
[NC_001453]	Strongylocentrot. purpuratus	Sea urchin	13	2	-	-
[NC_000933]	Metridium senile	Brown sea anemone	13	2	1	-
[NC_001328]	Caenorhabditis elegans	Soil nematode	12	1 (1)	-	-
[NC_001224]	Saccharomyces cerevisiae	Baker's yeast	7	3	11	1
[NC_001326]	Schizosaccharomyces pombe	Fission yeast	6	2	-	4
[NC_000895]	Dictyostelium discoideum	Slime mold	2(13)	2	14	11
[NC_001677]	Chondrus crispus	Irish moss/Red algae	18(1)	2 (1)	5	1
[NC_002007]	Porphyra purpurea	Seaweed/Red algae	16(3)	2	6	6
[NC_001638]	Chlamydomonas reinhardtii	Green algae	7	11(3)	0(1)	-
[NC_000892]	Pedinomonas minor	Green algae	11	3	-	-
[NC_001660]	Marchantia polymorpha	Liverwort	13(2)	3	17	43
[NC_001284]	Arabidopsis thaliana	Thale cress	19(3)	2 (1)	8	87

ISSN: 1471-2164