Table I. Threading results of putative plant GPCRs split into families of proteins that share discernible homology.

Putative plant GPCRs with GPCRs hit are denoted with single asterisks; no GPCR hits are denoted with double asterisks. Each hit has an associated interpretation, such as high, medium, or low, to indicate the expected reliability. Proteins predicted not to be 7TM proteins are underlined, and the expected number of transmembrane helices is given. Nonplant 7TM lung receptors are shown in italics. The following MtN3 proteins had no hits: At1g21460, At3g16690, At3g48740, and At5g13170. The following expressed protein family 2 proteins had no hits: At1g10660 and At5g62960. The following expressed protein family 3 protein had no hits: At3g09570. All of the expressed protein family 5 proteins had no hits: At3g63310 and At4g02690. All of the GNS1/SUR4 membrane family proteins had no hits: At1g75000, At3g06470, and At4g36830. All of the MLO family proteins had no hits: At1g11000, At1g26700, At1g24560, At2g33670, At2g44110, At4g24250, and At5g53760. Both of the GTG family proteins had no hits: GTG1 (nine-transmembrane helical) and GTG2 (nine-transmembrane helical). The groups are those reported by Moriyama et al. (2006).

TAIR Locus Identifier	I-TASSER	LOMETS	HHpred	FUGUE	Phyre
Nodulin MtN3 family proteins (8/17; two hits/eight proteins)
At3g28007	**	**	**	* (guess)	**
At4g25010	**	**	* (guess)	**	**
Expressed protein family 2 (one hit/three proteins)
At2g47115	**	**	* (uncertain)	**	**
Expressed protein family 3 (one hit/two proteins)
At5g42090	**	**	* (guess)	**	**
TOM3 family proteins
At1g14530	**	**	* (marginal)	**	**
At2g02180	**	**	* (guess)	**	**
At4g21790	**	**	* (marginal guess)	* (guess)	**
Lung_7-TM_R
At2g01070	**	* (high)	* (guess)	**	* (high)
Q22938_CAEEL	* (high)	**	* (high)	**	**
A8K285_HUMAN	**	**	* (guess)	**	**
YHB7_YEAST	**	* (marginal)	* (high)	**	**