| Non-specific acid phosphatase (NSAP) (EC 3.1.3.2) | phoN STM4319 | P26976 | 1 |
| Nonspecific ribonucleoside hydrolase | nuh PA0143 | Q9I6Y9 | 1 |
| NptA protein (Fragment) | VSAK1_11103 | A6D9G1 | 1 |
| NspA (Fragment) | nspA | C6ZG61 | 1 |
| Nss | SPJ_1665 | C1CFY9 | 1 |
| Nucleoid occlusion factor SlmA | slmA VSAK1_26715 | A6D8W0 | 1 |
| Nucleoid-associated protein PA3849 | PA3849 | Q9HXF7 | 1 |
| Nucleoid-associated protein Rv3716c | Rv3716c MTV025.064c | P9WNR9 | 1 |
| Nucleoid-associated protein Smlt1015 | Smlt1015 | B2FR75 | 1 |
| Nucleoid-associated protein SPy_1862/M5005_Spy1580 | SPy_1862 M5005_Spy1580 | P67268 | 1 |
| Nucleoid-associated protein VSAK1_03539 | VSAK1_03539 | A6CXK0 | 1 |
| Nucleoside channel receptor of phage T6 and colicin K | tsx KPN_00363 | A6T5E4 | 1 |
| Nucleoside channel receptor of phage T6 and colicin K | tsx SCH_0454 | Q57SF1 | 1 |
| Nucleoside diphosphate kinase (NDK) (NDP kinase) (EC 2.7.4.6) (Nucleoside-2-P kinase) | ndk Fphi_0549 | B0U0L6 | 1 |
| Nucleoside diphosphate kinase (NDK) (NDP kinase) (EC 2.7.4.6) (Nucleoside-2-P kinase) | ndk FTN_0271 | A0Q4L4 | 1 |
| Nucleoside diphosphate kinase (NDK) (NDP kinase) (EC 2.7.4.6) (Nucleoside-2-P kinase) | ndk KPN78578_27970 KPN_02848 | A6TCD7 | 1 |
| Nucleoside diphosphate kinase (NDK) (NDP kinase) (EC 2.7.4.6) (Nucleoside-2-P kinase) | ndk ABSDF3006 | B0VKS3 | 1 |
| Nucleoside diphosphate kinase (NDK) (NDP kinase) (EC 2.7.4.6) (Nucleoside-2-P kinase) | ndk B195_11591 | M5QYL7 | 1 |
| Nucleoside diphosphate kinase (NDK) (NDP kinase) (EC 2.7.4.6) (Nucleoside-2-P kinase) | ndk PP_0849 | Q88PK1 | 1 |
| Nucleoside diphosphate kinase (NDK) (NDP kinase) (EC 2.7.4.6) (Nucleoside-2-P kinase) | ndk YPO2883 y1349 YP_2749 | Q8ZCT2 | 1 |
| Nucleoside diphosphate kinase (NDK) (NDP kinase) (EC 2.7.4.6) (Nucleoside-2-P kinase) | ndk b2518 JW2502 | P0A763 | 1 |
| Nucleoside diphosphate kinase (NDK) (NDP kinase) (EC 2.7.4.6) (Nucleoside-2-P kinase) | ndk SAOUHSC_01485 | Q2FYG7 | 1 |
| Nucleoside diphosphate kinase regulator | rnk PA5274 | Q9HTS6 | 1 |
| Nucleoside permease | VSAK1_10853 | A6D218 | 1 |
| Nucleoside permease | nupC SCH_2412 | Q57LU4 | 1 |
| Nucleoside permease NupC (Nucleoside-transport system protein NupC) | nupC cru b2393 JW2389 | P0AFF2 | 1 |
| Nucleoside transporter, NupC family | AC1_1680 | B1R5X0 | 1 |
| Nucleoside-binding protein | Reut_B3989 | Q46U39 | 1 |
| Nucleoside-diphosphate-sugar epimerase | B195_06820 | M5QY20 | 1 |
| Nucleoside-specific channel-forming protein Tsx | ETAE_2935 | D0ZDY9 | 1 |
| Nucleoside-specific channel-forming protein tsx | tsx SF0348 S0356 | P0A929 | 1 |
| Nucleotide sugar dehydrogenase | VSAK1_09528 | A6D0E6 | 1 |
| Nucleotide-binding protein SPy_0652/M5005_Spy0539 | SPy_0652 M5005_Spy0539 | P67113 | 1 |
| O-acetylserine sulfhydrylase (OAS sulfhydrylase) (OASS) (EC 2.5.1.47) (Cysteine synthase A) (CSase A) (O-acetylserine (thiol)-lyase A) (OAS-TL A) (O-acetylserine-specific cysteine synthase) (Sulfide-dependent cysteine synthase) | cysK1 cysK Rv2334 MTCY98.03 | P9WP55 | 1 |
| O-acetyltransferase OatA (EC 2.3.1.-) | oatA SAOUHSC_02885 | Q2FV54 | 1 |
| O-antigen export system ATP-binding protein orfbB (EC 3.6.3.40) | OOM_0833 | I2AYR5 | 1 |
| O-antigen ligase | rfaL waaL b3622 JW3597 | P27243 | 1 |
| O-succinylbenzoate-CoA ligase (EC 6.2.1.26) | menE EDWATA_02772 | D4F7N6 | 1 |
| O-succinylhomoserine sulfhydrylase (OSH sulfhydrylase) (OSHS sulfhydrylase) (EC 2.5.1.-) | metZ Rv0391 | P9WGB5 | 1 |
| Octaprenyl-diphosphate synthase | ispB NMB0326 | Q7DDR3 | 1 |
| Oligoendopeptidase F | VSAK1_24785 | A6CZ13 | 1 |
| OLIGOPEPTIDASE | pepF jhp_0422 | Q9ZM03 | 1 |
| Oligopeptidase A | prlC FTN_0425 | A0Q513 | 1 |
| Oligopeptidase A | VSAK1_12885 | A6D266 | 1 |
| Oligopeptidase A (EC 3.4.24.70) | Fphi_0413 | B0U002 | 1 |
| Oligopeptidase A (EC 3.4.24.70) | prlC NMB0214 | Q9K1E2 | 1 |
| Oligopeptidase A (EC 3.4.24.70) | opdA YPO3975 | Q7CG05 | 1 |
| Oligopeptidase B (EC 3.4.21.83) | ptrB YPO1780 | Q74UT4 | 1 |
| Oligopeptide ABC transporter, ATP-binding protein | VSAK1_03364 | A6CXG5 | 1 |
| Oligopeptide ABC transporter, ATP-binding protein, putative | SAOUHSC_00926 | Q2FZR4 | 1 |
| Oligopeptide ABC transporter, periplasmic oligopeptide-binding protein | VC_1091 | Q9KT14 | 1 |
| Oligopeptide ABC transporter, permease protein | VSAK1_03354 | A6CXG3 | 1 |
| Oligopeptide ABC transporter, substrate-binding protein, putative | SAOUHSC_00927 | Q2FZR3 | 1 |
| Oligopeptide permease ABC transporter membrane protein | oppB VSAK1_03349 | A6CXG2 | 1 |
| Oligopeptide transport ATP-binding protein AmiE | amiE spr1704 | P0A2U9 | 1 |
| Oligopeptide transport ATP-binding protein OppD | oppD b1246 JW1238 | P76027 | 1 |
| Oligopeptide transport ATP-binding protein OppF | oppF b1247 JW1239 | P77737 | 1 |
| Oligopeptide transport ATP-binding protein OppF | oppF SPy_0297 M5005_Spy0253 | P0A2V6 | 1 |
| Oligopeptide transporter ATP-binding component | oppD VSAK1_03359 | A6CXG4 | 1 |
| Oligopeptide/dipeptide ABC transporter, ATP-binding protein | AC3_2880 | B1BQS7 | 1 |
| Oligopeptide/dipeptide ABC transporter, oligopeptide/dipeptide-binding protein | CPC_2588 | B1BMX8 | 1 |
| Oligopeptidepermease | oppB SPy_0294 | Q9A1F9 | 1 |
| Oligopeptidepermease (ATP-binding protein) | oppD SPy_0296 | Q9A1F7 | 1 |
| Oligoribonuclease (EC 3.1.-.-) | orn VSAK1_11338 | A6D9J7 | 1 |
| Omp1-like protein | SC1083_0143 | G4A5Q8 | 1 |
| OmpA domain protein | MXAN_5194 | Q1D1X6 | 1 |
| OmpA domain protein | MXAN_3163 | Q1D7K7 | 1 |
| OmpA family lipoprotein | B195_03862 | M5R2Q4 | 1 |
| OmpA family peptidoglycan-associated lipoprotein | OOM_0340 | I2AXI7 | 1 |
| OmpA family protein | B195_11021 | M5QH83 | 1 |
| OmpA family protein | OOM_0329 | I2AXH6 | 1 |
| OmpA family protein | FSU_2078 | A7UG37 | 1 |
| OmpA family protein | FSU_2396 | A7UG61 | 1 |
| OmpA family protein | FSU_3077 | C9RLT0 | 1 |
| OmpA family protein | FSU_0180 | C9RP29 | 1 |
| OmpA family protein | FSU_1609 | C9RQ78 | 1 |
| OmpA family protein | FTT_0831c | Q5NGK6 | 1 |
| OmpA-like outer membrane protein | SC1083_1928 | G4AAQ2 | 1 |
| OmpA-like transmembrane domain protein | ACINWCA92_3610 | L9LXP1 | 1 |
| Ompa-related protein | MXAN_6415 | Q1CYI4 | 1 |
| OmpA/MotB | B195_19211 | M5QDD9 | 1 |
| OmpA/MotB | PP1Y_AT640 | F6IFG7 | 1 |
| OmpA/MotB | NSU_2187 | G6ECW6 | 1 |
| OmpA/MotB domain protein | ETAE_1904 | D0Z8H2 | 1 |
| OmpA/MotB domain-containing protein | B195_05840 | M5QJI4 | 1 |
| OmpW | NSU_1841 | G6EBX0 | 1 |
| OmpW family protein | B195_13421 | M5QIL9 | 1 |
| OmpW family protein | ACINWC136_2748 | K9C882 | 1 |
| OmpW family protein | ACIN5021_2881 | L9LZG6 | 1 |
| OORB subunit of 2-oxoglutarate:acceptor oxidoreductase | oorB Cj0537 | Q0PAX9 | 1 |
| OORC subunit of 2-oxoglutarate:acceptor oxidoreductase | oorC Cj0538 | Q0PAX8 | 1 |
| Opa15063G | opa15063G | Q50943 | 1 |
| Opa1700 outer membrane protein (Fragment) | opaD1700 | O33388 | 1 |
| Opacity outermembrane protein (Fragment) | opa | Q51124 | 1 |
| Opacity outermembrane protein (Fragment) | opa | Q51125 | 1 |
| Opacity outermembrane protein (Fragment) | opa | Q51126 | 1 |
| Opacity protein (Fragment) | opaD | Q51085 | 1 |
| Opacity protein (Fragment) | opa | O07275 | 1 |
| Opacity protein (Opacity protein Opa102) (Fragment) | opa opaB | O07287 | 1 |
| Opacity protein opA53 (Fragment) | opaA | Q04876 | 1 |