>cd06136 TREX1_2 Three prime repair exonuclease (TREX) 1 and 2 are closely related DEDDh-type DnaQ-like 3'-5' exonucleases. They contain three conserved sequence motifs known as ExoI, II, and III, with a specific Hx(4)D conserved pattern at ExoIII. These motifs contain four conserved acidic residues that participate in coordination of divalent metal ions required for catalysis. Both proteins play a role in the metabolism and clearance of DNA. TREX1 is the major 3'-5' exonuclease activity detected in mammalian cells. Mutations in the human TREX1 gene can cause Aicardi-Goutieres syndrome (AGS), which is characterized by perturbed innate immunity and presents itself as a severe neurological disease. TREX1 degrades ssDNA generated by aberrant replication intermediates to prevent checkpoint activation and autoimmune disease. There are distinct structural differences between TREX1 and 2 that point to different biological roles for these proteins. The main difference is the presence of about 7

Probab=98.62 E-value=1.5e-06 Score=60.87 Aligned_cols=81 Identities=20% Similarity=0.234 Sum_probs=51.6 Q ss_pred HHHHHC--CCCCEEEEEEH-HHHHHHHHHH---CCCCCCC-CCEEEHHHHHHHHCCCCCHHHHHHHC-CCCCCHHHHHHH Q ss_conf 999863--88981999730-7749999986---0899884-20331688999867899968989982-998110043799 Q gi|254781193|r 57 LKEALE--NTDVTIVAHNS-YFERTVLKAC---FNLDIPI-HRWICTLVLARSNGLPSALKAVGEAL-KLSSQKMEEGKE 128 (675) Q Consensus 57 l~~~L~--~~~~~kV~HNa-~FD~~~L~~~---~Gi~i~~-~~~~DTmi~A~~l~~~~sL~~la~~l-~l~~~k~~~~k~ 128 (675) T Consensus 88 ~~~F~~~~~~~~~LVAHNa~~FD~~fL~~e~~r~g~~~p~~~~~iDtL~l~r~~~--~~L~~l~~~~~gi~~~------- 158 (177) T cd06136 88 IKLFLRRQPKPICLVAHNGNRFDFPILRSELERLGTKLPDDILCVDSLPAFRELD--QSLGSLYKRLFGQEPK------- 158 (177) T ss_pred HHHHHHHCCCCCEEEECCCHHCCHHHHHHHHHHCCCCCCCCCEEEEEHHHHHHHC--CCHHHHHHHHCCCCCC------- T ss_conf 9999962677867996485123799999999986998998988998607645506--9999999997599998------- Q ss_pred HHHHHCCCCCCCCCCCCCCCCCHHHHHHHHHHHHHHHHHHHHHHHH Q ss_conf 9986202112343323467858532899999989989999999963 Q gi|254781193|r 129 LIARFCKGETHECLYDRNKPNHREAWRLFGEYCKGDVTVTREIFKR 174 (675) Q Consensus 129 l~~~~~k~~~~~~~~~~~~~~~~~~~~~~~~Ya~~Dv~~t~~L~~~ 174 (675) T Consensus 159 -------------------~a---------HRAl~Da~at~~vflh 176 (177) T cd06136 159 -------------------NS---------HTAEGDVLALLKCALH 176 (177) T ss_pred -------------------CC---------CCCHHHHHHHHHHHCC T ss_conf -------------------77---------7848999999999757

HHsearch alignment for GI: 254781193 and conserved domain: cd06136