The detection in December 2019 of a cluster of pneumonia cases in Wuhan City, China, with no known cause prompted a rapid response from health authorities. 1,2 Within a month a novel coronavirus 2019-nCoV, also named Wuhan seafood market pneumonia virus isolate Wuhan-Hu-1, had been identified as the causative agent and a preliminary genome sequence had been released to the research community, followed by 3 more accurate iterations lodged in Genbank. At the time of writing there have been >9000 confirmed cases and the virus has spread to 20 countries (Australia, Cambodia, Canada, China, Finland, France, Germany, India, Italy, Japan, Republic of Korea, Malaysia, Nepal, Philippines, Singapore, Sri Lanka, Thailand, United Arab Emirates, United States of America, Vietnam), culminating in the World Health Organization declaring the outbreak of 2019-nCoV to be a Public Health Emergency of International Concern (PHEIC). Whilst efforts to understand the biology of the virus have begun with a view to producing an early vaccine, global efforts to contain the outbreak are currently concentrated on rapid development of diagnostics, detection of infected persons, their isolation and treatment. In the next phase, work will begin on finding new specific drugs to treat 2019-nCoV infections, and structural biology of the viral proteins will play a key role. In a previous communication we reported initial homology models for the 3CLpro encoded by the Wuhan novel coronavirus (2019-nCoV 3CLpro). Beta coronaviruses such as Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS) coronavirus generally contain a second, papain-like protease (PL pro ), which in concert with 3CL pro process the two viral polyproteins encoded by two open reading frames orf1a and orf1ab. In addition to their normal processing of viral polyproteins, the PL pro from SARS and MERS have also been shown to have de-ubiquitination and de-ISGylation functions. MERS PL pro also affects host innate immune response by interfering with the interferon regulatory factor 3 (IRF3) pathway. SARS and MERS PL pro enzymes have a preference for cleaving substrates after two glycine residues. In contrast to 3CLpro which utilises a Cys/His catalytic dyad, papain-like proteases from MERS and SARS possess a classical Asp/His/Cys catalytic triad. They also possess a Cterminal zinc-finger like domain consisting of two b-hairpins bearing four cysteine residues which coordinate a Zn 2+ ion with tetrahedral geometry (Figure ). The zinc-binding region has been shown through mutagenesis of the cysteine residues be crucial for both structural integrity and catalytic function. The N-terminal region is a ubiquitin-like (Ubl) domain which is not directly involved in the proteolytic function of PL pro . The central "thumb" domain is primarily comprised of a-helices and contributes the catalytic Cys112 to the active site. The C-terminal region is predominantly b-sheet and contains the fingers domain and also the "palm" region which bears the other two residues of the catalytic triad His275, Asp287. In this current work we now report the preparation of homology models of 2019-nCoV PL pro based on SARS and MERS X-ray crystallographic templates.