Table 3.
Characteristics of the wheat PDI-like proteins.
| Name | Length | Mw | pI | N-glycisilation sites (putative) | Domain compositiona | Active site sequence | Conserved charge pair sequenceb | Conserved arginineb |
|---|---|---|---|---|---|---|---|---|
| TaPDIL1-1a | 515 | 56.59 | 4.99 | 1: N283 | a-b-b'-a' | CGHC, CGHC | E62-K96, E406-K439 | R136, R475 |
| TaPDIL1-1b | 512 | 56.44 | 5.03 | 1: N283 | a-b-b'-a' | CGHC, CGHC | E62-K96, E406-K439 | R136, R475 |
| TaPDIL1-1c | 515 | 56.63 | 4.96 | 1: N283 | a-b-b'-a' | CGHC, CGHC | E62-K96, E406-K439 | R136, R475 |
| TaPDIL2-1 | 588 | 63.80 | 4.61 | 2: N109, N212 | c-a-b-b'-a' | CGHC, CGHC | E123-K157, E464-K497 | R193, R535 |
| TaPDIL3-1 | 541 | 59.61 | 4.95 | 1: N150 | c-a-b-b'-a' | CERS, CVDC | L90-K124, E429-R462 | R160, O492 |
| TaPDIL4-1a | 367 | 40.27 | 6.17 | 0 | a°-a-D | CGHC, CGHC | E54-K87, E173-K211 | R125, R244 |
| TaPDIL4-1b | 367 | 40.26 | 6.17 | 0 | a°-a-D | CGHC, CGHC | E54-K87, E173-K211 | R125, R244 |
| TaPDIL5-1a | 440 | 47.15 | 5.12 | 1: N170 | a°-a-b | CGHC, CGHC | E51-K89, E188-K226 | R119, R257 |
| TaPDIL5-1b | 440 | 47.22 | 5.36 | 1: N170 | a°-a-b | CGHC, CGHC | E51-K89, E188-K226 | R119, R257 |
| TaPDIL6-1a | 151 | 16.99 | 4.96 | 0 | a | CKHC | Q56-S95 | R126 |
| TaPDIL6-1b | 149 | 16.65 | 5.30 | 0 | a | CKHC | Q54-S93 | R124 |
| TaPDIL7-1a | 413 | 46.30 | 4.91 | 1: N275 | a-b-b'-t | CGHC | D56-K90 | R126 |
| TaPDIL7-1b | 417 | 46.62 | 4.91 | 2: N176, N279 | a-b-b'-t | CGHC | D60-K94 | R130 |
| TaPDIL7-1c | 413 | 46.32 | 4.87 | 2: N172, N275 | a-b-b'-t | CGHC | D56-K90 | R126 |
| TaPDIL7-2a | 418 | 46.40 | 5.12 | 0 | a-b-b'-t | CGHC | D64-K98 | R134 |
| TaPDIL7-2b | 418 | 46.34 | 5.03 | 1: N384 | a-b-b'-t | CGHC | D64-K98 | R134 |
| TaPDIL8-1 | 485 | 54.41 | 6.90 | ND | t-a-t | CYWS | N164-K203 | R249 |
a a = active site containing thioredoxin-like domain; b = inactive thioredoxin-like domain (note that the superscript are included to distinguish between domains of proteins containing more than one a and b domain on the basis of their position and not on the basis of sequence homology); c = acidic segment; D = Erp29c domain; t = transmembrane domain. b The position of conserved charge pair sequence and arginine residues that are considered important for the catalytic activity of different members of the human PDI family are determined on the basis of multiple alignments of the a type domains of wheat PDI-like proteins and human classical PDI [Accession number P07237] (Figure 3). ND = not determined because TaPDIL8-1 lacks a putative N-terminal signal peptide. Proteins without signal peptides are unlikely to be exposed to N-glycosilation machinery and thus may not be glycosylated in vivo even though they contain potential motifs.