Caulimoviridae. Caulimoviridae

Description of Caulimoviridae adapted from ICTVdb Virion Properties Morphology Virions consist of a capsid. Virus capsid is not enveloped. Capsid is round to elongated with icosahedral symmetry (T=7). The capsid is isometric, or bacilliform and has a diameter of 35-50 nm. The capsid shells of virions are composed of multiple layers. The capsomer arrangement is not obvious. The bacilliform capsid has a length of 130 nm, or 60-900 nm and a width of 24-30-35 nm. Physicochemical and Physical Properties Virions have a buoyant density in CsCl of 1.3-1.312-1.4 g cm-3. There are 1 sedimenting component(s) found in purified preparations, or 2 sedimenting component(s) found in purified preparations. The sedimentation coefficient is 200-251-285 S20w; of the other(s) are 212 S20w. Isoelectric point pH is 4. The thermal inactivation point (TIP) is at 55-60-90°C. The longevity in vitro (LIV) is 1-28-85 days. Although the titer is dependent on the host, the decimal exponent (DEX) of the dilution end point is usually around 3-4. The infectivity is not changed by treatment with ether; retained when deproteinized with proteases, or decreased when deproteinized with proteases; retained when deproteinized with phenol or detergent. Nucleic Acid The Mr of the genome constitutes 14.5-16.08-17% of the virion by weight. The genome is not segmented and contains a single molecule or two segments of open circular reverse transcribing double-stranded DNA. Minor species of non-genomic nucleic acid are not found in virions. The genome is sequenced, and complete sequence is about 6800-7680-8300 nucleotides long. The genome has a guanine + cytosine content of 28-35.5-43 %. The genome has terminally redundant sequences. The terminally redundant sequences have direct terminal repeats; are reiterated internally in inverted form. The genome has single-stranded discontinuities at specific sites; transcribed strand has one discontinuity (or more, non-transcribed strand has one discontinuity (or more). The genome has an intergenic poly (A) region, or no intergenic poly (A) region. Proteins Proteins constitute about 83-84.41-85.9% of the particle weight. The viral genome encodes structural proteins and non-structural proteins. Virions consist of 1 structural protein(s), or 3 structural protein(s). Non-Structural Proteins: The virus codes for an RNA-dependent DNA polymerase. Lipids Lipids are not reported. Genome Organization and Replication Transcription: The virus codes for 2-8 ORF(s). Sub-genomic RNA is present in infected cells. Translation: The genome replicates in the nucleus, or the cytoplasm. Replication involves

花椰菜病毒科（Caulimoviridae）数据集描述改编自国际病毒分类委员会数据库（ICTVdb）：
### 病毒粒子特性
病毒粒子由衣壳构成。病毒衣壳无包膜，呈圆形至长条形，具二十面体对称（T=7）；衣壳为等轴对称形态，或呈杆状，直径介于35~50纳米之间。病毒粒子的衣壳壳层由多层结构组成，衣壳粒的排布并不明显。杆状衣壳的长度为130纳米，或60~900纳米，宽度为24~30~35纳米。

### 理化与物理特性
病毒粒子在氯化铯中的浮力密度为1.3~1.312~1.4克每立方厘米。纯化制备物中可检测到1种沉降组分，或2种沉降组分。主沉降组分的沉降系数为200~251~285 S₂₀w，其余组分的沉降系数为212 S₂₀w。等电点pH为4。热灭活点（thermal inactivation point, TIP）为55~60~90℃。体外存活期（longevity in vitro, LIV）为1~28~85天。尽管病毒滴度取决于宿主，但稀释终点的十进制指数（decimal exponent, DEX）通常约为3~4。病毒的感染性不受乙醚处理影响；经蛋白酶脱蛋白后，感染性保持不变，或有所降低；经苯酚或去污剂脱蛋白后，感染性得以保留。

### 核酸特性
病毒基因组的相对分子质量占病毒粒子总质量的14.5~16.08~17%。基因组不进行分段，包含1个开环反转录双链DNA分子，或2个该类DNA片段。病毒粒子中未发现非基因组来源的次要核酸组分。该基因组已完成测序，完整序列长度约为6800~7680~8300个核苷酸。基因组的鸟嘌呤（G）与胞嘧啶（C）总含量为28~35.5~43%。基因组带有末端冗余序列，该序列包含正向末端重复序列，并以反向重复的形式在基因组内部进行重复。基因组在特定位点存在单链缺口：转录链存在1个（或多个）缺口，非转录链同样存在1个（或多个）缺口。基因组带有基因间poly(A)区域，或不带有该区域。

### 蛋白质特性
蛋白质约占病毒粒子总质量的83~84.41~85.9%。病毒基因组编码结构蛋白与非结构蛋白两类蛋白。病毒粒子包含1种结构蛋白，或3种结构蛋白。
非结构蛋白：病毒编码RNA依赖的DNA聚合酶。

### 脂质特性
未检测到脂质组分。

### 基因组组织与复制
转录过程：病毒编码2~8个开放阅读框（Open Reading Frame, ORF）。感染宿主的细胞中存在亚基因组RNA。
翻译与复制：基因组在细胞核，或细胞质中进行复制。复制过程涉及