ID 1.11.1.26 DE NADH-dependent peroxiredoxin. AN alkyl hydroperoxide reductase. CA a hydroperoxide + H(+) + NADH = an alcohol + H2O + NAD(+). CC -!- Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant CC proteins. CC -!- They can be divided into three classes: typical 2-Cys, atypical 2-Cys CC and 1-Cys peroxiredoxins. CC -!- The peroxidase reaction comprises two steps centered around a redox- CC active cysteine called the peroxidatic cysteine. CC -!- All three peroxiredoxin classes have the first step in common, CC in which the peroxidatic cysteine attacks the peroxide substrate and CC is oxidized to S-hydroxycysteine (a sulfenic acid). CC -!- The second step of the peroxidase reaction, the regeneration of CC cysteine from S-hydroxycysteine, distinguishes the three CC peroxiredoxin classes. CC -!- For typical 2-Cys Prxs, in the second step, the peroxidatic CC S-hydroxycysteine from one subunit is attacked by the 'resolving' CC cysteine located in the C-terminus of the second subunit, to form an CC intersubunit disulfide bond, which is then reduced by one of several CC cell-specific thiol-containing reductants completing the catalytic CC cycle. CC -!- In the atypical 2-Cys Prxs, both the peroxidatic cysteine and its CC resolving cysteine are in the same polypeptide, so their reaction CC forms an intrachain disulfide bond. CC -!- The 1-Cys Prxs conserve only the peroxidatic cysteine, so its CC regeneration involves direct interaction with a reductant molecule. CC -!- This bacterial peroxiredoxin differs from most other forms by CC comprising two types of subunits. CC -!- One subunit (AhpC) is a typical 2-Cys peroxiredoxin. CC -!- Following the reduction of the substrate, one AhpC subunit forms a CC disulfide bond with an identical unit. CC -!- The disulfide bond is reduced by the second type of subunit (AhpF). CC -!- This second subunit is a flavin-containing protein that uses CC electrons from NADH to reduce the cysteine residues on the CC AhpC subunits back to their active state. CC -!- Formerly EC 1.11.1.15. DR P82954, AHPC_ACICA ; K0J4Q8, AHPC_AMPXN ; P80239, AHPC_BACSU ; DR P57279, AHPC_BUCAI ; Q8K9W0, AHPC_BUCAP ; Q89AS1, AHPC_BUCBP ; DR P83117, AHPC_DELAC ; P0AE10, AHPC_ECO57 ; P0AE09, AHPC_ECOL6 ; DR P0AE08, AHPC_ECOLI ; P26830, AHPC_FERAY ; P56876, AHPC_HELPJ ; DR P21762, AHPC_HELPY ; Q02UU0, AHPC_PSEAB ; P72314, AHPC_RHORU ; DR P0A252, AHPC_SALTI ; P0A251, AHPC_SALTY ; P0AE11, AHPC_SHIFL ; DR Q2FJN4, AHPC_STAA3 ; P0A0B7, AHPC_STAA8 ; Q2YVK2, AHPC_STAAB ; DR Q5HIR5, AHPC_STAAC ; P0A0B5, AHPC_STAAM ; P99074, AHPC_STAAN ; DR Q6GJR7, AHPC_STAAR ; Q6GC91, AHPC_STAAS ; P0A0B6, AHPC_STAAW ; DR Q5HRY1, AHPC_STAEQ ; Q8CMQ2, AHPC_STAES ; Q4L376, AHPC_STAHJ ; DR Q49UT8, AHPC_STAS1 ; //