second cyclin box found in cyclin-J (CCNJ) family; The CCNJ family includes two cyclins, CCNJ and CCNJ-like. CCNJ may regulate the cell cycle or transcription. Members of this family contain two cyclin boxes. This model corresponds to the second one. The cyclin box is a protein binding domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767938619  87 PTPAHFLDYYLLASVSQKDHHChTWPTTCPRKTKECLKEYAHYFLEVTLQDHIFYKFQPSVVAAACVGASRICLQLSPYW 166
Cdd:cd20529    1 PTPAHFLEYYLSQGVLFVDDHD-GLPSELLEKVKEYVRKYADFFLDLSLQDYAFLNYKPSLLAAACIAAARKALGLSPTW 79

                         90       100
                 ....*....|....*....|..
gi 767938619 167 TRDLQRISSYSLEHLSTCIEIL 188
Cdd:cd20529   80 PEELEKLTGYSEDELEPCVELL 101

second cyclin box found in cyclin-J (CCNJ) family; The CCNJ family includes two cyclins, CCNJ and CCNJ-like. CCNJ may regulate the cell cycle or transcription. Members of this family contain two cyclin boxes. This model corresponds to the second one. The cyclin box is a protein binding domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767938619  87 PTPAHFLDYYLLASVSQKDHHChTWPTTCPRKTKECLKEYAHYFLEVTLQDHIFYKFQPSVVAAACVGASRICLQLSPYW 166
Cdd:cd20529    1 PTPAHFLEYYLSQGVLFVDDHD-GLPSELLEKVKEYVRKYADFFLDLSLQDYAFLNYKPSLLAAACIAAARKALGLSPTW 79

                         90       100
                 ....*....|....*....|..
gi 767938619 167 TRDLQRISSYSLEHLSTCIEIL 188
Cdd:cd20529   80 PEELEKLTGYSEDELEPCVELL 101

domain present in cyclins, TFIIB and Retinoblastoma; A helical domain present in cyclins and TFIIB (twice) and Retinoblastoma (once). A protein recognition domain functioning in cell-cycle and transcription control.

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 767938619   127 AHYFLEVTLQDHIFYKFQPSVVAAACVGASRICLQLSPyWTRDLQRISSY-SLEHLSTCIEILL 189
Cdd:smart00385  20 AVNLLDRFLSDYKFLKYSPSLIAAAALYLASKTEETPP-WTKELVHYTGYfTEEEILRMERLLL 82

second cyclin box found in cyclin-J (CCNJ) family; The CCNJ family includes two cyclins, CCNJ and CCNJ-like. CCNJ may regulate the cell cycle or transcription. Members of this family contain two cyclin boxes. This model corresponds to the second one. The cyclin box is a protein binding domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767938619  87 PTPAHFLDYYLLASVSQKDHHChTWPTTCPRKTKECLKEYAHYFLEVTLQDHIFYKFQPSVVAAACVGASRICLQLSPYW 166
Cdd:cd20529    1 PTPAHFLEYYLSQGVLFVDDHD-GLPSELLEKVKEYVRKYADFFLDLSLQDYAFLNYKPSLLAAACIAAARKALGLSPTW 79

                         90       100
                 ....*....|....*....|..
gi 767938619 167 TRDLQRISSYSLEHLSTCIEIL 188
Cdd:cd20529   80 PEELEKLTGYSEDELEPCVELL 101

second cyclin box found in cyclin-O (CCNO) and similar proteins; This subfamily is composed of CCNO and similar proteins including Schizosaccharomyces pombe meiosis-specific cyclin rem1, Drosophila melanogaster G2/mitotic-specific cyclin-A (CCNA), and Candida albicans G1/S-specific cyclin CCN1, among others. Rem1 is required for pre-meiotic DNA synthesis and S phase progression. CCNA is essential for the control of the cell cycle at the G2/M (mitosis) transition. CCN1 is essential for the control of the cell cycle at the G1/S (start) transition and for maintenance of filamentous growth. CCNO is specifically required for generation of multiciliated cells, possibly by promoting a cell cycle state compatible with centriole amplification and maturation. It is involved in the activation of cyclin-dependent kinase 2. Members of this subfamily contain two cyclin boxes. This model corresponds to the second one. The cyclin box is a protein binding domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767938619  87 PTPAHFLDYYL-LASVSQKDHHChtwpttcprktkeclkeyAHYFLEVTLQDHIFYKFQPSVVAAACVGASRICLQLSPY 165
Cdd:cd20537    1 PTPLSFLRRYLsLLGLDEKVRHL------------------ARYLLELSLLDYEFLKYRPSLIAAAALYLARKILGEPPP 62

                         90       100
                 ....*....|....*....|....*....
gi 767938619 166 WTRDLQRISSYSLEHLSTCIEILLVVYDN 194
Cdd:cd20537   63 SPQLLQLVTGYSENDLQECAKELLELLAQ 91

second cyclin box found in Arabidopsis thaliana A-type cyclins (CycAs) and similar proteins; Plant A-type cyclins (CycAs) correspond to a group of G2/mitotic-specific cyclins that are functionally linked to S- and M-phases of the mitotic cycle, which predicts their involvement also in meiosis. CycAs associate with their partner cyclin-dependent kinases (CDKs) to trigger the kinase activity. They contain two cyclin boxes. This model corresponds to the second one. The cyclin box is a protein binding domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767938619  87 PTPAHFLDYYLlaSVSQKDHhchtwpttcPRKTKECLkeyAHYFLEVTLQDHIFYKFQPSVVAAACVGASRICLQLSPyW 166
Cdd:cd20506    1 PTIKTFLRRFL--RAAQASV---------PDLKLEFL---ANYLAELSLLDYEFLKYLPSLIAASAVFLARHTLNPHP-W 65

                         90       100
                 ....*....|....*....|..
gi 767938619 167 TRDLQRISSYSLEHLSTCIEIL 188
Cdd:cd20506   66 NPTLEHYTGYKAADLKPCVQAL 87

second cyclin box found in yeast B-type cyclins; The family includes Saccharomyces cerevisiae G2/mitotic-specific cyclins 1-4 (ScCLB1-4), S-phase entry cyclins 5-6 (ScCLB5-6), and Schizosaccharomyces pombe G2/mitotic-specific cyclins, cig1, cig2 and cdc13. ScCLB1-4 are essential for the control of the cell cycle at the G2/M (mitosis) transition. They interact with the CDC2 protein kinase to form maturation promoting factor (MPF). ScCLB5-6 interact with CDC28 and are involved in DNA replication in Saccharomyces cerevisiae. ScCLB5 is required for efficient progression through S phase and possibly for the normal progression through meiosis. ScCLB6 is involved in G1/S and or S phase progression. Cig1 is required for efficient passage of the G1/S transition. Cig2 and cdc13 are essential for the control of the cell cycle at the G2/M and G1/S (mitosis) transition. They interact with the cdc2 protein kinase to form MPF. Members in this family contain two cyclin boxes. This model corresponds to the second one. The cyclin box is a protein binding domain.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 767938619 127 AHYFLEVTLQDHIFYKFQPSVVAAACVGASRICLQlSPYWTRDLQRISSYSLEHLSTCIEILL 189
Cdd:cd20512   23 AKYLLEITILDHRFLGYPPSLLAAAAMYLARKMLG-RGDWNDNLVHYSGYTESQLIPCADIML 84

domain present in cyclins, TFIIB and Retinoblastoma; A helical domain present in cyclins and TFIIB (twice) and Retinoblastoma (once). A protein recognition domain functioning in cell-cycle and transcription control.

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 767938619   127 AHYFLEVTLQDHIFYKFQPSVVAAACVGASRICLQLSPyWTRDLQRISSY-SLEHLSTCIEILL 189
Cdd:smart00385  20 AVNLLDRFLSDYKFLKYSPSLIAAAALYLASKTEETPP-WTKELVHYTGYfTEEEILRMERLLL 82

second cyclin box found in cyclin-O (CCNO); CCNO is specifically required for generation of multiciliated cells, possibly by promoting a cell cycle state compatible with centriole amplification and maturation. It acts downstream of MCIDAS (multiciliate differentiation and DNA synthesis associated cell cycle protein) to promote mother centriole amplification and maturation in preparation for apical docking. CCNO is involved in the activation of cyclin-dependent kinase 2. CCNO contains two cyclin boxes. This model corresponds to the second one. The cyclin box is a protein binding domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 767938619  87 PTPAHFLDYYLLASVSQKDHHChtwpTTCPRKTKeCLkeyAHYFLEVTLQDHIFYKFQPSVVAAACVgasRICLQLSPYW 166
Cdd:cd20722    1 PTLQFFLEHFSSLRLENRELSC----AEEARKAR-AL---ARYLAELSLADYAFNQYPPSLLAICSL---ELADRMLQHR 69

                         90       100
                 ....*....|....*....|
gi 767938619 167 TRDLQRISSYSLEHLSTCIE 186
Cdd:cd20722   70 SPITERLSGYPQSALEDCVG 89

second cyclin box found in plant cyclin-delta family; This subfamily is composed of plant delta family cyclins, including a group of G1/S-specific D-type cyclins from Arabidopsis thaliana which may activate the cell cycle in the root apical meristem (RAM) and promote embryonic root (radicle) protrusion. Members of this family contain two cyclin boxes. This model corresponds to the second one. The cyclin box is a protein binding domain.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 767938619  88 TPAHFLDYyLLASVSQKDHHCHtwpttcprktkecLKEYAHYFLEVTLQDHIFYKFQPSVVAAA 151
Cdd:cd20544    2 TPFSFLDY-FISKIGLSDSREE-------------LLSRATELLLSTTKDIRFLEYRPSVIAAA 51

second cyclin box found in G2/mitotic-specific cyclin-F (CCNF) and similar proteins; CCNF, also termed F-box only protein 1 (FBXO1), is a substrate recognition component of a SCF (SKP1-CUL1-F-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of CP110 during G2 phase, thereby acting as an inhibitor of centrosome reduplication. It is the largest among all cyclins and oscillates in the cell cycle like other cyclins. CCNF contains two cyclin boxes. This model corresponds to the second one. The cyclin box is a protein binding domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 767938619 127 AHYFLEVTLQDHIFYKFQPSVVAAACVGASRICLQLSPYWTRDLQRISSYSLEHLSTC 184
Cdd:cd20522    3 ASYICELSLLHTELGRYSPAVIAASCLLLARVLLNQALPWPSQLEEFTGFSLEDLLSC 60

Cyclin box fold superfamily; The cyclin box is a protein binding domain that functions in cell-cycle and transcriptional control. It is about 100 amino acids in length, composed of five helices, and is present in cyclins, transcription initiation factor IIB (TFIIB), and retinoblastoma tumour suppressor protein (Rb). Cyclins consist of 8 classes of cell cycle regulators that function as regulatory subunits of cyclin-dependent kinases (CDKs), which are serine/threonine kinases. The catalytic activities of CDKs are modulated not only by their interactions with cyclins but also by CDK inhibitors (CKIs). CDKs, cyclins and CKIs play key roles in transcription, epigenetic regulation, metabolism, stem cell self-renewal, neuronal functions, and spermatogenesis. TFIIB is a transcription factor that binds the TATA box. Members in this superfamily contain one or two copies of the cyclin box.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 767938619 124 KEYAHYFLEVTLQDHIFYKFQPSVVAAACV-GASRICLQlsPYWTRDLQRISSYSLEHLSTCIEI 187
Cdd:cd00043   20 LELAIELLDRFLSKGLLLGRSPELIAAACLyLACKLEEL--PRTLKEIAKVSGVSEKELRKAEKE 82