2. b.40.1 Staphylococcal nuclease OB-fold barrel, closed or partly opened n=5, S=10 or S=8; greek-key 1joq d1joqa_ A:15-19,21-28,29-36,57-69,71-76 1stg d1stga_ A:15-19,21-28,29-36,54-70,71-76 1joo d1jooa_ A:15-19,21-28,29-36,54-70,71-76 2snm d2snma_ A:15-19,21-28,29-36,54-69,71-76 1enc d1enca_ A:15-19,21-28,29-36,52-70,71-76 1ez6 d1ez6a_ A:15-19,21-28,29-36,54-69,71-76 1snc d1snca_ A:15-19,21-28,29-36,54-69,71-76 1snq d1snqa_ A:15-19,21-28,29-36,54-69,71-76 1u9r d1u9ra_ A:15-19,21-28,29-36,54-69,71-76 1snm d1snma_ A:15-19,21-28,29-36,54-69,71-76 1ena d1enaa_ A:15-19,21-28,29-36,52-69,71-76 2enb d2enba_ A:15-19,21-28,29-36,54-69,71-76 1a2t d1a2ta_ A:15-19,21-28,29-36,54-69,71-76 1snp d1snpa_ A:15-19,21-28,29-36,54-69,71-76 1eyc d1eyca_ A:15-19,21-28,29-36,54-69,71-76 1ii3 d1ii3a_ A:15-19,21-28,29-36,54-69,71-76 1aex d1aexa_ A:15-19,21-28,29-36,54-69,71-76 1a2u d1a2ua_ A:15-19,21-28,29-36,54-69,71-76 1syd d1syda_ A:15-19,21-28,29-36,54-69,71-76 1kdb d1kdba_ A:15-19,21-28,29-36,54-69,71-76 1syg d1syga_ A:15-19,21-28,29-36,54-69,71-76 1ey5 d1ey5a_ A:15-19,21-28,29-36,54-69,71-76 1sno d1snoa_ A:15-19,21-28,29-36,54-69,71-76 1ihz d1ihza_ A:15-19,21-28,29-36,54-69,71-76 1ey0 d1ey0a_ A:15-19,21-28,29-36,54-69,71-76 1eya d1eyaa_ A:15-19,21-28,29-36,52-69,71-76 1kdc d1kdca_ A:15-19,21-28,29-36,54-69,71-76 1kab d1kaba_ A:15-19,21-28,29-36,54-69,71-76 1kda d1kdaa_ A:15-19,21-28,29-36,54-69,71-76 1tt2 d1tt2a_ A:15-19,21-28,29-36,54-69,71-76 1ey4 d1ey4a_ A:15-19,21-28,29-36,54-69,71-76 1ey7 d1ey7a_ A:15-19,21-28,29-36,54-69,71-76 1f2m d1f2ma_ A:15-19,21-28,29-36,54-69,71-76 3nuc d3nuca_ A:15-19,21-28,29-36,54-69,71-76 1jor d1jora_ A:15-19,21-28,29-36,54-70,71-76 1f2z d1f2za_ A:15-19,21-28,29-36,54-69,71-76 1ey9 d1ey9a_ A:15-19,21-28,29-36,52-69,71-76 1ey8 d1ey8a_ A:15-19,21-28,29-36,52-69,71-76 1syc d1syca_ A:15-19,21-28,29-36,52-69,71-76 1sye d1syea_ A:15-19,21-28,29-36,52-69,71-76 1ez8 d1ez8a_ A:15-19,21-28,29-36,52-69,71-76 1eyd d1eyda_ A:15-19,21-28,29-36,52-69,71-76 2nuc d2nuca_ A:15-19,21-28,29-36,52-69,71-76 1sth d1stha_ A:15-19,21-28,29-36,52-69,71-76 1ey6 d1ey6a_ A:15-19,21-28,29-36,52-69,71-76 1eqv d1eqva_ A:15-19,21-28,29-36,52-69,71-76 1sty d1stya_ A:15-19,21-28,29-36,52-69,71-76 1a3t d1a3ta_ A:15-19,21-28,29-36,52-69,71-76 1stn d1stna_ A:15-19,21-28,29-36,52-69,71-76 1syf d1syfa_ A:15-19,21-28,29-36,52-69,71-76 5nuc d5nuca_ A:15-19,21-28,29-36,54-69,71-76 1f2y d1f2ya_ A:15-19,21-28,29-36,52-69,71-76 1a3u d1a3ua_ A:15-19,21-28,29-36,52-69,71-76 1a3v d1a3va_ A:15-19,21-28,29-36,52-69,71-76 1nuc d1nuca_ A:15-19,21-28,29-36,52-69,71-76 1snd d1sndb_ B:15-19,21-28,29-36,52-69,71-76 1rkn d1rkna_ A:12-18,21-27,32-36,61-70,71-77 1jok d1joka_ A:15-19,21-28,29-36,51-69,71-77 5. d.153.2 Archaeal IMP cyclohydrolase PurO has a putative active site in the same topological location as the Ntn hydrolase but lacks the N-terminal nucleophile ! Ntn hydrolase-like 4 layers: alpha/beta/beta/alpha; has an unusual sheet-to-sheet packing 2ntl d2ntlb1 B:29-36,37-44,58-66,162-173,181-191 2ntl d2ntlc1 C:29-36,37-44,58-66,162-173,181-191 2ntl d2ntld1 D:29-36,37-44,58-66,162-173,181-191 2ntl d2ntla1 A:29-36,37-44,58-66,162-173,181-191 2ntm d2ntma1 A:29-36,37-44,58-66,162-173,181-191 2ntm d2ntmc1 C:29-36,37-44,58-66,162-173,181-191 2ntk d2ntka1 A:29-36,37-44,58-66,162-173,181-191 2ntk d2ntkb1 B:29-36,37-44,58-66,162-173,181-191 2ntk d2ntkd1 D:29-36,37-44,58-66,162-173,181-191 2ntk d2ntkc1 C:29-36,37-44,58-66,162-173,181-191 2ntm d2ntmd1 D:29-36,37-44,58-66,162-173,181-191 1kuu d1kuua_ A:29-36,37-44,58-66,162-173,181-191 2ntm d2ntmb1 B:29-36,37-44,58-66,162-173,181-191 8. d.75.1 tRNA-intron endonuclease N-terminal domain-like MutS N-terminal domain-like beta(2)-alpha-beta(2)-alpha-beta(2); 2 layers, alpha/beta 1a79 d1a79a2 A:9-16,17-22,41-46,46-57,99-106 1a79 d1a79c2 C:9-16,17-22,41-46,46-57,99-106 1r0v d1r0va3 A:148-155,156-161,177-182,182-193,231-237 1r0v d1r0vb3 B:148-155,156-161,177-182,182-193,231-237 1r0v d1r0vc3 C:148-155,156-161,177-182,182-193,231-237 1r0v d1r0vd3 D:148-155,156-161,177-182,182-193,231-237 1r11 d1r11a4 A:148-155,156-161,177-182,182-193,231-237 1rlv d1rlvb4 B:148-155,156-161,177-182,182-193,231-237 1rlv d1rlva4 A:148-155,156-161,177-182,182-193,231-237 1r11 d1r11b4 B:148-155,156-161,177-182,182-193,231-237 2gjw d2gjwc4 C:150-157,158-163,179-184,184-195,233-239 2gjw d2gjwb4 B:150-157,158-163,179-184,184-195,233-239 1a79 d1a79b2 B:9-16,17-22,41-46,46-57,101-106 1a79 d1a79d2 D:9-16,17-22,41-46,46-57,101-106 2gjw d2gjwd4 D:154-158,159-164,180-185,185-196,234-240 2gjw d2gjwa4 A:154-158,159-164,180-185,185-196,234-240 10. d.261.1 Hypothetical protein PH1602 Hypothetical protein PH1602 complex alpha+beta fold; contains a region of similarity to the ferredoxin-like fold 1uc2 d1uc2a_ A:5-9,11-16,24-30,31-42,71-75 1uc2 d1uc2b_ B:5-9,11-16,24-30,31-42,71-75 13. e.13.1 DNA primase core DNA primase core 2 domains: (1) alpha+beta; (2) toprim alpha/beta 1eqn d1eqnb_ B:157-163,201-211,213-222,266-277,280-285 1nui d1nuia1 A:95-102,103-114,116-126,158-170,174-179 1nui d1nuib1 B:95-102,103-114,116-126,158-170,174-179 1q57 d1q57f2 F:95-102,103-114,116-126,158-170,174-179 1q57 d1q57b2 B:95-102,103-114,116-126,158-170,174-179 1q57 d1q57g2 G:95-102,103-114,116-126,158-170,174-179 1q57 d1q57c2 C:95-102,103-114,116-126,158-170,174-179 1q57 d1q57e2 E:95-102,103-114,116-126,158-170,174-179 1q57 d1q57d2 D:95-102,103-114,116-126,158-170,174-179 14. b.59.1 XRCC4, N-terminal domain an HTH motif connects strands 4 and 5 ! XRCC4, N-terminal domain barrel, closed; n=7, S=10; order: 1234765; strands 1 and 5 are parallel to each other 1fu1 d1fu1a1 A:17-25,31-39,40-48,62-76,92-102 1fu1 d1fu1b1 B:417-425,431-439,440-448,462-476,492-502 1ik9 d1ik9b1 B:17-25,31-39,40-48,62-76,92-102