In all four anammox species we studied, DsbD, a thiol-disulfide membrane transporter involved in the aforementioned pathway, is annotated successfully and with high confidence by a similar comparative methodology adopted for CcsA and CcsB (Table  2 and Additional file 6). In detail, two DsbD homologs are identified in Kuenenia whereas a single copy is retrieved for strain KSU-1 and Brocadia. All DsbD homologs share similar structural features, including 8-11 transmembrane helices and conserved cysteine Salubrinal mw residues [22]. Scalindua contains a homolog of CcdA, related to but click here shorter than DsbD, possessing only

6 transmembrane helices along with two cysteine residues [23]. DsbD is a housekeeping thiol-disulphide electron shuttle [24] and as such it is not an indispensable cytochrome c maturation System II component. In contrast, CcsX (sometimes called ResA) that fulfils the essential role of apocytochrome c reduction in this disulfide bond cascade is a dedicated membrane-anchored thiol-disulfide oxidoreductase of maturation System II. Apart from the conserved thioredoxin cytochrome c recognition motif (CXXC), CcsX also possesses additional cysteine residues and a single transmembrane helix through which it is anchored to the membrane. Our comparative computational

approach identified multiple potential CcsX homologs for each anammox genus. Particularly, two CcsX-like homologs for Brocadia, three for Kuenenia and six for each, Scalindua and strain KSU-1, were identified with high SAHA HDAC research buy confidence

(Additional file 6). However, homologs possessing no signal peptide sequences were ruled out from our final collective table (Table  2). Although distinction between the dedicated CcsX proteins and other thioredoxins that might possess similar features cannot be made, the presence of that many CcsX-like homologs suffices for a complete c-type cytochrome maturation System II. Table 2 CcsX and DsbD homologs identified in four anammox genera Homolog Resminostat Anammox genus Gene product Length (aa) BLAST* HHPRED** HMMER** Motif Additional Cys residues TMHs Signal peptide CcsX Kuenenia kuste0860 161 ✓ ✓ ✓ CX2C 1 ✓ ✗ kuste0967 166 ✓ ✓ ✓ CX2C 1 ✓ ✗ kuste3827 164 ✓ ✓ ✓ CX2C 3 ✓ ✓ Scalindua scal02124 172 ✓ ✓ ✓ CX2C 0 ✓ ✓ scal00014c 173 ✓ ✓ ✓ CX2C 3 ✓ ✓ scal02421c 255 ✓ ✓ ✓ CX2C 1 ✓ ✓ scal02845 125 ✓ ✓ ✓ CX2C 0 ✗ ✗ scal00012c 185 ✓ ✗ ✓ CX2C 1 ✗ ✓ scal04176 164 ✓ ✓ ✓ CX4C 1 ✗ ✗ KSU-1 GAB64172.1 312 ✓ ✓ ✓ CX2C 1 ✓ ✗ GAB61322.1 165 ✓ ✓ ✓ CX2C 2 ✓ ✓ GAB62714.1 162 ✓ ✓ ✓ CX2C 1 ✓ ✓ GAB64222.1 163 ✓ ✓ ✓ CX2C 1 ✓ ✓ GAB64221.1 163 ✓ ✓ ✓ CX2C 0 ✓ ✓ GAB62039.1 669 ✓ ✓ ✓ CX2C 8 ✓ ✗ Brocadia BFUL_03119 163 ✓ ✓ ✓ CX2C 0 ✓ ✓ BFUL_00886 173 ✓ ✓ ✓ CX2C 2 ✗ ✓ DsbD Kuenenia kuste2732 601 ✓ ✓ ✓ NA 7 8 NA kustc0946 608 ✓ ✓ ✓ NA 8 9 NA KSU-1 GAB61320.