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  • General

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  • 病毒结构

    Representation of the HIV virus, showing its outer structure with knobs.

    Is this a cell or a virus?
    ::这是细胞还是病毒?

    It is actually a representation of the , the virus that causes AIDS. All the little “knobs” on the outside of the virus help to give the virus structure. And it is this structure that must be identified by a vaccine .
    ::事实上,它代表了导致艾滋病病毒的病毒。病毒外部的所有小“手柄”都有助于病毒结构的形成。而这种结构必须由疫苗来识别。

    Structure of Viruses
    ::病毒结构结构

    Viruses vary in their structure. A virus particle consists of or within a protective coat called a capsid . The shape of the capsid may vary from one type of virus to another. The capsid is made from the proteins that are encoded by viral genes within their genome .
    ::病毒在结构上各有不同。病毒粒子由一种叫做卡比西的防护外衣组成或内装。卡比西的形状可能因病毒类型而异。卡比西是用基因组内病毒基因编码的蛋白质制成的。

    The shape of the capsid serves as one basis for of viruses. The capsid of the virus shown in Figure is icosahedral. Virally coded proteins will self-assemble to form a capsid. Some viruses have an envelope of phospholipids and proteins. The envelope is made from portions of the host’s . It surrounds the capsid and helps protect the virus from the host’s immune system . The envelope may also have receptor molecules that can bind with host . They make it easier for the virus to infect the cells.
    ::胶囊形状是病毒的一个基础。 图中显示的病毒的封状是象形体。 气态编码蛋白质可以自行组装成胶囊。 有些病毒有磷素和蛋白质的包装物。 信封由宿主的部分组成。 它环绕着封状,帮助保护病毒不受宿主免疫系统的影响。 信封中可能还有与宿主结合的受体分子。 它们使得病毒更容易感染细胞。

    Illustration shows a cytomegalovirus structure with labeled components like genome, capsid, and glycoprotein.

    Diagram of a Cytomegalovirus. The capsid encloses the genetic material of the virus. The envelope which surrounds the capsid is typically made from portions of the host cell membranes (phospholipids and proteins). Not all viruses have a viral envelope.
    ::Cytomegalo 病毒的图解。 胶囊包含了病毒的遗传物质。 围绕胶囊的包包通常由主机细胞膜的部分( 磷脂和蛋白质) 组成。 并非所有病毒都有病毒包。

    Helical Viruses
    ::肝肝病毒

    Helical capsids are made up of a single type of protein subunit stacked around a central axis to form a helical structure. The helix may have a hollow center, which makes it look like a hollow tube. This arrangement results in rod-shaped or filamentous virions . These virions can be anything from short and very rigid, to long and very flexible. The well-studied tobacco mosaic virus (TMV) is an example of a helical virus, as seen in the Figure .
    ::螺旋体是由一种单类蛋白分元素组成的,它堆在中央轴周围,形成一个螺旋结构。螺旋体可能有一个空心中心,这使它看起来像一个空心管。这种安排导致杆状或丝状的病毒。这些病毒可以是短的、非常僵硬的、长的和非常灵活的。如图所示,经过仔细研究的烟草混合病毒(TMV)是热利病毒的一个例子。

    The structure of the tobacco mosaic virus, highlighting nucleic acid, protein units, and capsid.

    A helical virus, tobacco mosaic virus. Although their diameter may be very small, some helical viruses can be quite long, as shown here. 1. Nucleic acid; 2. Viral protein units, 3. Capsid. TMV causes tobacco mosaic disease in tobacco, cucumber, pepper, and tomato plants.
    ::一种螺旋病毒,一种烟草混凝土病毒。虽然它们的直径可能很小,但如本文所示,有些螺旋病毒可能很长。 1. 核酸; 2. 活性蛋白单位; 3. 硫酸。 TMV在烟草、黄瓜、胡椒和番茄植物中造成烟草混凝土疾病。

    Icosahedral Viruses
    ::Icosahedr病毒

    Icosahedral capsid symmetry gives viruses a spherical appearance at low magnification, but the protein subunits are actually arranged in a regular geometrical pattern, similar to a soccer ball; they are not truly spherical. An icosahedral shape is the most efficient way of creating a hardy structure from multiple copies of a single protein. This shape is used because it can be built from a single basic unit protein which is used over and over again. This saves space in the viral genome.
    ::Icosahedral 羊角对称法使病毒在低放大度时出现球形外观,但蛋白质亚单位实际上是按常规几何模式排列的,类似于足球球;它们并不真正球形。 象形形状是利用一个蛋白质的多个复制件创建硬体结构的最有效方法。 使用这个形状是因为它可以从一个不断使用过的单一基本单位蛋白质中构建。 这节省了病毒基因组的空间 。

    Microscopic view of adenoviruses, illustrating icosahedral virus structure with triangular facets.

    Adenovirus, an icosahedral virus. An icosahedron is a three-dimensional shape made up of 20 equilateral triangles. Viral structures are built of repeated identical protein subunits, making the icosahedron the easiest shape to assemble using these subunits.
    ::亚丁病毒是一种象形病毒。 象形体是由20个等边三角组成的三维形状。 维拉尔结构是由重复相同的蛋白子单位组成的, 使象形体成为使用这些子单位最容易组装的形状。

    Complex Viruses
    ::复杂病毒

    Complex viruses possess a capsid which is neither purely helical, nor purely icosahedral, and which may have extra structures such as protein tails or a complex outer wall. Viral protein subunits will self-assemble into a capsid, but the complex viruses DNA also codes for proteins which help in building the viral capsid. Many phage viruses are complex-shaped; they have an icosahedral head bound to a helical tail. The tail may have a base plate with protein tail fibers. Some complex viruses do not have tail fibers.
    ::复杂的病毒具有一种包皮,它既不纯粹是螺旋型的,也不是纯粹的象形的,而且可能具有蛋白尾巴或复杂的外墙等额外结构。活性蛋白亚单位将自我组装成一个罩骨,但复杂的病毒DNA也含有有助于建立病毒尾部的蛋白质编码。许多象形病毒是复杂的;它们有一个象形头,紧贴着一个螺旋尾巴。尾部可能有一个带有蛋白尾纤维的底板。有些复杂的病毒没有尾部纤维。

    Diagrams illustrating the structures of complex viruses, showcasing head, tail, and fibers.

    This “moon lander”-shaped complex virus infects Escherichia coli bacteria.
    ::这种“月球登陆者”形状的复杂病毒感染了Esherichia大肠细菌。

    Enveloped Viruses
    ::病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒 病毒

    Some viruses are able to surround (envelop) themselves in a portion of the cell membrane of their host. The virus can use either the outer membrane of the host cell, or an internal membrane such as the nuclear membrane or . In this way the virus gains an outer bilayer known as a viral envelope . This membrane is studded with proteins coded for by both the viral genome and the host genome. However, the lipid membrane itself and any present come entirely from the host cell. The influenza virus, HIV, and the varicella zoster virus ( Figure ) are enveloped viruses.
    ::某些病毒可以环绕其宿主的细胞膜的一部分。 病毒可以使用宿主细胞的外膜, 也可以使用内膜, 如核膜, 也可以使用内膜。 这样病毒就产生了一个外双层, 称为病毒信封。 这种膜由病毒基因组和宿主基因组编码的蛋白组成。 但是, 脂肪膜本身和任何出现都完全来自宿主细胞。 流感病毒、 艾滋病毒和类zoster病毒( Figure ) 是包扎病毒 。

    Enveloped varicella zoster virus, causing chickenpox and shingles, displays a lipid bilayer structure.

    An enveloped virus. Varicella zoster virus causes chicken pox and shingles.
    ::一种包装病毒 瓦里切拉的雄性动物病毒导致天花和虫

    The viral envelope can give a virus some advantages over other capsid-only viruses. For example, they have better protection from the host's immune system, and certain chemicals. The proteins in the envelope can include glycoproteins, which act as receptor molecules. These receptor molecules allow host cells to recognize and bind the virions, which may result in easier uptake of the virion into the cell. Most enveloped viruses depend on their envelopes to infect cells. However, because the envelope contains lipids, it makes the virus more susceptible to inactivation by environmental agents, such as detergents that disrupt lipids.
    ::病毒信封可以给病毒一些优势, 而不是其他只覆盖病毒。 例如, 它们可以更好地保护病毒不受宿主的免疫系统和某些化学物质的影响。 信封中的蛋白质可以包括作为受体分子的甘蓝蛋白。 这些受体分子可以让宿主细胞识别和捆绑病毒, 这可能使得病毒更容易被吸收到细胞中。 大多数被覆盖的病毒都取决于信封感染细胞。 但是, 信封中含有脂质, 这使得病毒更容易被环境物剂( 如干扰脂肪的洗涤剂) 侵入。

       

     

    Summary
    ::摘要

    • Viruses have different shapes. They can be cylindrical, icosahedral, complex, or enveloped.
      ::病毒有不同的形状。它们可以是圆柱形的, 象形的, 复杂的,或包封的。

    Review
    ::回顾

    1. Describe variation in capsid shape in viruses.
      ::描述病毒封盖形状的变异。
    2. Compare the structures of a prokaryote and a virus. If you prefer, you may draw a diagram of each and label the different parts of each structure.
      ::比较 prokaryote 和 病毒 的结构。 如果您愿意, 您可以绘制每个结构的图表, 并给每个结构的不同部分贴上标签 。