>TIGR01382 PfpI intracellular protease, PfpI family; InterPro: IPR006286 Peptidases are grouped into clans and families. Clans are groups of families for which there is evidence of common ancestry. Each clan is identified with two letters, the first representing the catalytic type of the families included in the clan (with the letter 'P' being used for a clan containing families of more than one of the catalytic types serine, threonine and cysteine). Some families cannot yet be assigned to clans, and when a formal assignment is required, such a family is described as belonging to clan A-, C-, M-, S-, T- or U-, according to the catalytic type. Some clans are divided into subclans because there is evidence of a very ancient divergence within the clan, for example MA(E), the gluzincins, and MA(M), the metzincins. Families are grouped by their catalytic type, the first character representing the catalytic type: A, aspartic; C, cysteine; G, glutamic acid; M, metallo; S, serine; T, threonine; and U, unknown. The serine, threonine and cysteine peptidases utilise the amino acid as a nucleophile and form an acyl intermediate - these peptidases can also readily act as transferases. In the case of aspartic, glutamic and metallopeptidases, the nucleophile is an activated water molecule. Cysteine peptidases have characteristic molecular topologies, which can be seen not only in their three-dimensional structures, but commonly also in the two-dimensional structures. These are peptidases in which the nucleophile is the sulphydryl group of a cysteine residue. Cysteine proteases are divided into clans (proteins which are evolutionary related), and further sub-divided into families, on the basis of the architecture of their catalytic dyad or triad . This group of cysteine peptidases belong to MEROPS peptidase family C56 (Pfp1 endopeptidase, clan PC(C)). The member of this family from Pyrococcus horikoshii has been solved to 2 Angstrom resolution. It is an ATP-independent intracellular protease that crystallises as a hexameric ring. Cys-101 is proposed as the active site residue in a catalytic triad with the adjacent His-102 and a Glu residue from an adjacent monomer. A member of this family from Bacillus subtilis, GSP18, has been shown to be expressed in response to several forms of stress. A role in the degradation of small peptides has been suggested. This family is contained in a larger one of the thiamine biosynthesis protein ThiJ and its homologs.; GO: 0016798 hydrolase activity acting on glycosyl bonds.

Probab=96.96  E-value=0.00012  Score=53.51  Aligned_cols=83  Identities=20%  Similarity=0.352  Sum_probs=57.1

Q ss_pred             EEEECCCCHHHHHHHHHHHCCCEEEEECCCCCHHHHHHCCCCEEEECCCCCCCC----CCCCCCCCHHHHHCCCCEEEEC
Q ss_conf             999889705788998888659406985289898899723997999985388999----9999753768980899889977
Q gi|254780414|r   11 LIIDFGSQFTQLIARRVRESKVYCEVIAFKNALDYFKEQNPQAIILSGSPASSL----DIDSPQIPKEILESNIPLLGIC   86 (520)
Q Consensus        11 lIlDfGSQytqLIaRriRelgVyseI~P~~~~~e~i~~~~p~GIILSGGP~SV~----d~~ap~~~~~I~~~~iPILGIC   86 (520)
T Consensus        45 aihdfeGdqty~-----~~~g~---~v~vd~~~~~v~~~~YDal~ipGG~a~~e~LR~d~~~~~lvR~f~e~gK~vaaIC  116 (189)
T TIGR01382        45 AIHDFEGDQTYT-----EKHGY---SVTVDATIDDVDPEDYDALVIPGGRASPEYLRLDEKVIRLVREFVEKGKPVAAIC  116 (189)
T ss_pred             EEECCCCCCCCC-----CCCCE---EEEEECCEECCCHHHCCEEEEECCCCCCCCCCCCHHHHHHHHHHHHCCCEEEEEE
T ss_conf             101156763213-----47881---6887441214785256478971773560001487689999999841788199984


Q ss_pred             HHHHHHHHHCCCEEEECC
Q ss_conf             899998997096999869
Q gi|254780414|r   87 YGQQIMCQSLGGKTKNSQ  104 (520)
Q Consensus        87 yG~QlLa~~~GG~V~~~~  104 (520)
T Consensus       117 hgp~lLi~A---~VlrGk  131 (189)
T TIGR01382       117 HGPQLLISA---GVLRGK  131 (189)
T ss_pred             CCCEEEEEC---CEECCC
T ss_conf             530000025---510375