Proteinase

Proteinase (PRO) are enzymes which hydrolyze peptide bonds. They are classified by the amino acid site of their cleavage or by the pH at which they are active. PRO B is a serine protease. For more details see Streptomyces griseus proteinase B. PRO A is a carboxylproteinase. PRO K is a serine protease which cleaves proteins preferentially after hydrophobic residues. Calcium ions contribute to the stability of the enzyme. PRO K is active over a wide pH range and is used in molecular biology to inactivate nucleases from preparations of DNA or RNA. PRO K is used in the partial proteolysis of lactoferrin into its N- and C-lobe. The two lobes of lactoferrin have different antimicrobial and antifungal properties. PRO K can digest hair (keratin). 3D structures of proteinase Updated on 30-May-2025 PRO A 2sga – SgPRO – Streptomyces griseus 2jxr, 1fmu, 1fmx – yPRO - yeast 1sgc - SgPRO + chymostatin A 3sga, 4sga, 5sga - SgPRO + polypeptide inhibitor 1dp5, 1dpj, 1g0v - yPRO + polypeptide inhibitor IA3 1fq5 - yPRO + inhibitor PRO B 3sgb – SgPRO + turkey ovomucoid inhibitor 1sgp, 1sgq, 1sgr, 1cso, 1ct0, 1ct2, 1ct4, 1ds2, 2sgp, 2nu3, 2nu4 – SgPRO + turkey ovomucoid inhibitor (mutant) 4sgb - SgPRO + potato inhibitor PRO K 2prk, 1cnm, 1egq, 2id8, 2g4v, 2v8b, 3gt3, 3gt4, 3d9q, 3ddz, 3de0 , 3de1, 3de2, 3de3, 3de4, 3de5, 3de6, 3de7, 3dvq, 3dvr, 3dvs, 3dw1, 3dw3, 3dwe, 3i2y, 3i30, 3i37, 3i34, 3l1k, 3aj8, 3aj9, 3q40, 3q5g, 3qmp, 4b5l, 4fon – EaPRO + Ca – Engyodontium album 1ic6 – EaPRO (mutant) + Ca 1ptk, 1ht3 – EaPRO + Ca + Hg 2pkc – EaPRO + Na 4dj5 – EaPRO PRO K complex with peptide 3prk, 1p7v, 1p7w – EaPRO + Ca + peptide inhibitor 1bjr, 2dqk, 2duj – EaPRO + Ca + lactoferrin peptide 2hd4 – EaPRO + Ca + lactoferrin peptide inhibitor 2dp4, 3ptl – EaPRO + lactoferrin peptide 1pek, 1pfg – EaPRO + peptide inhibitor 1pj8 – EaPRO + Hg + substrate analog peptide 2hpz, 2pq2 – EaPRO + Ca + peptide 3osz – EaPRO + Ca + antimicrobial peptide 2b6n – PRO + tripeptide - Serratia PRO K complex with small molecule 2pwb – EaPRO + Ca + coumarin 2pyz – EaPRO + Ca + auramine 2pwa – EaPRO + Ca + alanine boronic acid 1oyo – EaPRO + Ca + melanin monomer 3dyb – EaPRO + Ca + digalacturonic acid PRO 3C 1qa7 – PRO – Hepatitis virus 2vb0 - PRO – Coxsakievirus H2-PRO 1wni – PRO – Trimeresurus flavoviridis Aspartic PRO 2asi – PRO – Rhizomucor miehei 1zap – CaPRO – Candida albicans 1izd - AoPRO – Aspergillus oryzae 1eag – CaPRO + inhibitor 1fq4 - yPRO + inhibitor 1j71 - PRO + polypeptide inhibitor – Candida tropicalis 1ize - AoPRO + polypeptide-statin inhibitor 1wkr - PRO + polypeptide-statin inhibitor – Irpex lacteus Cysteine PRO 2hrv – PRO 2A – human rhinovirus Serine PRO 1s2n, 1sh7 – PRO – Vibrio 3s9a, 3s9b – RvPRO – Siamese Russell’s viper 3s9c, 3sbk – RvPRO + human factor V polypeptide 1ga1, 1ga4, 1ga6, 1nlu – PsPRO + iodotyrostatin fragment – Pseudomonas 1kdv, 1kdy, 1kdz, 1ke1, 1ke2 - PsPRO + polypeptide inhibitor

spinqualitylabelsall models E. coli proteinase K (grey) complex with lactoferrin peptide (green) and Ca+2 (green) and nitrate ions (PDB code 2duj) Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image