| [A] Sulfolobus acidocaldarius | SULAC01589 | Q4J857 | conserved protein |
| [A] Sulfolobus islandicus (strain L.S.2.15 / Lassen #1) | SULIL00422 | C3MLH8 | |
| [A] Sulfolobus islandicus (strain M.14.25 / Kamchatka #1) | SULIM00434 | C3MUW4 | |
| [A] Sulfolobus islandicus (strain M.16.27) | SULIA00452 | C3N2J5 | |
| [A] Sulfolobus islandicus (strain Y.G.57.14 / Yellowstone #1) | SULIY00405 | C3NA17 | |
| [A] Sulfolobus islandicus (strain Y.N.15.51 / Yellowstone #2) | SULIN02296 | C3NLI5 | |
| [A] Sulfolobus solfataricus | SULSO01862 | DLHH_SULSO | Putative carboxymethylenebutenolidase |
| [A] Sulfolobus tokodaii | SULTO02669 | Q96XK4 | hypothetical protein |
| [B] Frankia sp. (strain EAN1pec) | FRASN05915 | A8LCA3 | Carboxymethylenebutenolidase |
| [B] Rhodospirillum centenum (strain ATCC 51521 / SW) | RHOCS01470 | B6IN29 | Carboxymethylenebutenolidase, putative |
| [B] Bordetella bronchiseptica | BORBR01326 | Q7WMQ8 | ortholog of Bordetella pertussis (BX470248) BP2713 putative hydrolase |
| [B] Bordetella parapertussis | BORPA01106 | Q7WB90 | ortholog of Bordetella pertussis (BX470248) BP2713 putative hydrolase |
| [B] Bordetella pertussis | BORPE02488 | Q7VVF6 | Similar to Methylobacterium extorquens putative carboxymethylenebutenolidase SW:DLHH_METEX (P71505) (291 aa) fasta scores: E(): 4.8e-59, 56.8% id in 294 aa. Also similar to BP1256, 55.253% identity (55.469% ungapped) in 257 aa overlap. putative hydrolase |
| [B] Acidithiobacillus ferrooxidans (strain ATCC 23270 / DSM 14882 / NCIB 8455) | ACIF202075 | B7J5J8 | Carboxymethylenebutenolidase family protein |
| [B] Acidithiobacillus ferrooxidans (strain ATCC 53993) | ACIF501773 | B5EL00 | Carboxymethylenebutenolidase |
| [B] Enterobacter sakazakii (strain ATCC BAA-894) | ENTS803596 | A7MQM0 | Putative uncharacterized protein |