Question

2. Write a draft introduction which includes the following elements

What is the protein myosin? What are its function(s) ? Why it is so important? Any diseases?

What are the unconventional class I myosins?

What is known about your particular family of the class I myosins? What do we know about their mechanism of being targeted to the membrane? What chromosome is it present on?

What domain (s) in your sequence may be involved in its membrane targeting function? Which other kind of proteins house this domain? What is the structure-function relationship of this domain fold? Any characteristics or hallmarks? Is there is a canonical function?

What is known and not known about your assigned sequence specifically its membrane binding function ? What do you hope to find? What could be possible goals of your study using bioinformatics? Can you frame a hypothesis regarding the membrane binding behavior of your sequence?

PLEASEEEEE HELP. NEED AS MUCH INFORMATION AS I CAN GET.

Answer 1

1.Myosins are a family of ATP-dependent motor proteins and play an important role in the contraction of mucles and are involved in a wide range of motility processes in the eukaryotes. They are responsible for actin- based motility. Most eukaryotic cells contain iso myosins.

Mutation in the heavy chain genes of myosins can lead to various myopathic diseases like- cardiomyopathy and skeletal myopathy.

Myosin I was the first unconventional myosin discovered in 1973 and are single headed and are therefore unable to self-associate into bipolar filaments. Based on phylogenetic analysis myosins are divided into four subclasses: subclass C myr3, subclass a myr1, subclass b myr2, and subclass g myr4. Myosin I are mainly important in the endocytic pathway and can be localised to specialised compartments like the recycling of endosome or lysosome. A number of myosinI are regulated either by heavy chain phosphorylation by specific kinase or calcium binding to calmodulin in the neck region or possible to the tail domain targeting to specific receptors. However little is known about their regulation in the cellular level.

Subclass 1 C myr3 are also known as ameboid myosins are mostly present in vertebrates.It consists of a single motor domain followed by a neck region that consists of one or two IQ motifs which bind calmodulin-like subunits and a tail region that contain one to three 'Tail Homology Domain -H1-3). The role of subclass 1 myosin is mainly cell crawling, chemotaxis, phagocytosis, pseudopod extension and contractile vacuole function.

Subclass 2 a myr1 act as cross-links between the membrane and actin filament bundles.

Subclass 3 b myr2 tail region can bind phospholipids and associated with actin-rich structures in ruffles and protrusions in the plasma membrane of cultured neurons.

Subclass 4 g myr4 has a high range of tissue expression with the highest being shown in adult human brain. The tail region (TH1) is rich in the basic and hydrophobic residue.

I Dictyostelium MyoB (124 kDa) Mem bind SH3 GPQ I Vert. myosin Ia (119 kDa) Mem bind Sco IIVert. skeletal muscle myosin II (223 kDa) IIDrosophila ninac long (174 kDa) Kinase CS V Vert. myosin Va (212 kDa) DLC VI Vert. myosin VI (145 kDa) or VIIVert. myosin VIIa (250 kDa) H4 FERM SH3 MyTH4 FERM or IX Vert. myosin IXb (230 kDa) Zn2+rhoGAP X Vert. myosin X (-230 kDa) PH domainsMyTH4 FERM XV Vert. myosin XVa (395 kDa) FERM SH3 MyTH4 FERM MyTH4 100 amino aci = 1 IQ motif