Table 1.
Vitamin B12-related genes in sequenced marine eukaryotic phytoplankton genomes and select marine prokaryotic genomes.
| Auran | Phatr | Thaps | Psemu | Fracy | Emihu | Ostta | Ostlu | MicPu | Chlre | ChlNC | Syn 8102 | Pro 9313 | P. ubique | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MetH | 34875 | 23399 | 693 | 213031 | 207237 | 423073 | 16287 | 45056 | 148156 | 76715 | 36916 | SYNW 1238 | PMT0729 | x |
| MetE | x | 28056 | x | x | 228154 | x | x | x | x | 154307 | 141995 | x | x | x |
| MmcM | 26280 | 51830 | 33685 | 261420 | 273786 | 120906 417351 | x | x | x | x | 18280 | x | x | x |
| CBA1 | 63075 | 48322 | 11697 | 235642 | 241429, 246327, 273295, 269995 | x | x | x | x | x | x | x | x | x |
| RNR Class 2 B12 | x | x | x | x | x | x | x | x | x | x# | x | SYNW 1147 | PMT 0793 | x |
| RNR Class 1 Fe; small | 65685 59025 | 39306 17523 | 32555 8522 3367 | 67342 252139 | 268008 206256 | 470988 469622 200748 | 22908 8886 | 32923 39468 | 155636 174818 | 188785 144621 | 34102 10712 57791 | x | x | PB7211_302 |
| RNR Class 1 Fe; Large | 30730, 37557, 24558 | 42726, 45529 | 370, 268807 | 223844 319245 | 260490, 262570, 205957 | 449248, 212824 | 22667 | 48569 | 167892 | 185583 | 32953 | x | x | PU1002_00625 |
| B12 biosynthesis | No | No | No | No | No | No | No | No | No | No | No | Yes | Yes | No |
| B12 Aux. by genome | Yes | No | Yes | Yes | No | Yes | Yes | Yes | Yes | No | No | No | No | No |
| B12 Aux. by culture | Yes (Tang et al., 2010) | No (Droop, 1958) | Yes (Guillard and Ryther, 1962) | Yes (Tang et al., 2010)* | No (Helliwell et al., 2011) | See (Helliwell et al., 2011) | Yes (Helliwell et al., 2011) | Yes (Helliwell et al., 2011) | No (Provasoli and Carlucci, 1974) | No (Shihira and Krauss, 1965) |
The hypothesized vitamin requirements of each strain are also given, along with whether culture-based confirmation of auxotophic status is available. This table represents an expansion of information given in Croft et al., 2006 and Helliwell et al., 2011. No eukaryote is known to make vitamin B12; B12 auxotrophy in eukaryotic algae appears to depend on the presence or absence of B12-independent methionine synthase (Croft et al., 2005; Helliwell et al., 2011). Auran, Aureococcus anophagefferans; Phatr, Phaeodactylum tricornutum; Thaps, Thalassiosira pseudonanna; Psemu, Pseudo-nitzschia multiseries CLN-47; Fracyl, Fragilariopsis cylindrus; Chlre, Chlamydomonas reinhardtii (v4; filtered or best proteins); Emihu, Emiliania huxleyi; Ostta, Ostreococcus taurii; Ostlu, Ostreococcus lucimarinus V2 filtered model proteins; MicPu, Micromonas pusilla CCMP1545 c3.0, filtered model proteins; ChlNC, Chlorella sp. NC64A filtered proteins; Syn8102, Synechococcus sp. WH8102; Pro9313, Prochlorococcus marinus MIT 9313; P. ubique, Candidatus Pelagibacter ubique SAR11 HTCC1002.
Auxotrophy tested in culture of a different strain.
Has a protein with substantial sequence similarity but missing active site: (154521).